There are three ways to compare string in java: String类型比较不同对象内容是否相同,应该用equals,因为==用于比较引用类型和比较基本数据类型时具有不同的功能。 分析如下: String作为一个对象来使用. Compare strings to find out if they are equal: The equals() method compares two strings, Compara la cadena de texto contra un objeto. JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. String class provides two methods: public boolean equals (Object another) compares this string to the specified object. Es werden somit Referenzen überprüft, ob sie auf das selbe Objekt zeigen. In this article, we'll talk about the different ways of comparing Strings in Java. Wait a minute. Seit Java 7 erlaubt switch den Vergleich von String-Objekten mit einer Liste von Sprungzielen. Java String equals () Java String equals () method overrides the Object class equals () method implementation. 例子一:对象不同,内容相同,"=="返回false,equals返回true If other string object does not match the same sequence of characters of this object, it returns false. Die equals-Methode kennen Sie bereits vom Vergleichen zweier Strings. L'implémentation par défaut de la méthode equals () dans la classe Object renvoie true si et seulement si les deux références pointent vers la même instance. In this tutorial, we shall see how to check if two Strings are equal in Java using the method String.equals (String anotherString). If all the contents of both the strings are same then it returns true. If any character is not matched, it returns false. Devolverá true si las cadenas comparadas son iguales. We can compare string in java on the basis of content and reference. Home. Ein Parameter gibt die Kultur, Berücksichtigung von Groß- und Kleinschreibung und Sortierregeln, die für den Vergleich verwendet werden. The first statement creates a new string in the string pool. Java String equals() 方法 Java String类 equals() 方法用于将字符串与指定的对象比较。 String 类中重写了 equals() 方法用于比较两个字符串的内容是否相等。 语法 public boolean equals(Object anObject) 参数 anObject -- 与字符串进行比较的对象。 返回值 如果给定对象与字符串相等,则返回 true;否则返回 fa.. String equals () method always return boolean value, it doesn’t throw any exceptions. edit close. anotherObject : another object i.e. Il se comporte donc comme la comparaison par ==. Developed by JavaTpoint. Java – Check if two Strings are Equal. Java String.equals () method. "; String s2 = "CodeGym is the best website for learning Java! Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. If all characters are not matched then it returns false. Die equals-Methode kennen Sie bereits vom Vergleichen zweier Strings. true if characters of both strings are equal otherwise false. The following example creates a string array that consists of an uppercase "I", a lowercase "i", and a dotless "ı". equals() achtet auf absolute Übereinstimmung, und equalsIgnoreCase() ist für einen Vergleich zu haben, der unabhängig von der Groß-/Kleinschreibung ist. Example 1 – Check if two Strings are Equal String s1 = "CodeGym is the best website for learning Java! Equals, equalsIgnoreCase. Equals (String, String, StringComparison) Bestimmt, ob zwei angegebene String -Objekte denselben Wert haben. Um den Inhalt zu vergleichen, nutzt man deswegen die equals()-Methode in der Java-Programmierung. You should not use == (equality operator) to compare these strings because they compare the reference of the string, i.e. In diesem Kapitel wurde Ihnen erklärt, warum Strings bzw. and returns true if the strings are equal, and false if not. compared with this string. Below example illustrate the use of .equals for string comparison in Java: filter_none. Try watching this video on www.youtube.com, or enable JavaScript if it is disabled in your browser. We want to compare two strings for equality. There are three ways to compare strings in Java. The second statement simply refers to the same area of memory as s1. Feb 2016: F: Erste Schritte Hilfe bei Übung zu String equals() und Schleifen: Java Basics - Anfänger-Themen: 8: 16. Siehe auch das nachfolgende Beispiel für ein besseres Verständnis: public static void main(String[] args) { String a = new String("Hello World! str.equals(null). You could make another 500 identical strings and the result wouldn't change. Jedes Objekt kann selbst entscheiden ob es gleich einem anderen ist, deswegen hat jedes Objekt eine equals(Object o) Methode. Plutôt que de comparer des pointeurs, la classe String compare le contenu de la String. The equals method returns true if given string is equal to this string. Java에서 문자열을 비교하는 다양한 방법을 알아보겠습니다. If all the contents of both the strings are same then it returns true. length; if (n == anotherString. The equality is done in case-sensitive manner. In diesem Kapitel wurde Ihnen erklärt, warum Strings bzw. ... Un exemple d'implémentation equals() peut être trouvé dans la classe String, qui fait partie de l'API Java principale. Sie können auf unterschiedliche Weise gebildet werden, werden gegebenenfalls in einen Speicher eingetragen und müssen mit Vorsicht verglichen werden. equals() method compares two strings based on the string content. The is operator returns True if the two variables point to the same data object, else, it returns False.. Syntax: variable1 is variable2 Example: Java言語で文字列の値を比較したことがあるかと思います。Javaで文字列を比較するにはequalsを使う方法がありますが ==を使うのはだめなの? なぜequalsメソッドを使うの? Python “is” operator can be used to efficiently check for the equality of two string objects. The equals method returns true if given string is equal to this string. Using “==” Comparison Operator. str.equals(null). Compare strings to find out if they are equal, ignoring case differences: String myStr1 = "Hello"; String myStr2 = "HELLO"; String myStr3 = "Another String"; System.out.println(myStr1.equalsIgnoreCase(myStr2)); // true System.out.println(myStr1.equalsIgnoreCase(myStr3)); // false . In Java, string equals () method compares the two given strings based on the data/content of the string. Try it Yourself » Definition and Usage. equals() achtet auf absolute Übereinstimmung, und equalsIgnoreCase() ist für einen Vergleich zu haben, der unabhängig von der Groß-/Kleinschreibung ist. Object. mit der Methode equals() erfolgen. Two strings are considered equal ignoring case, if they are of the same length String class overrides equals () method from Object class. Below is an example of the equals… String comparison is a crucial part of working with strings in Java. Parameters: anObject - The object to compare this String … The String equals method looks at the two Java strings, and if they contain the exact same string of characters, they are considered equal. It is used in authentication (by equals() method), sorting (by compareTo() method), reference matching (by == operator) etc.. All rights reserved. The String class represents character strings. Diese vergleicht allerdings per default nur auf Identität, was of nicht gewünscht ist. If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail: W3Schools is optimized for learning and training. In equalsIgnoreCase() method, two strings are considered equal if they are of the same length and corresponding characters in the two strings are equal … If all characters are matched, it returns true. // String.java public boolean equals (Object anObject) {if (this == anObject) {return true;} if (anObject instanceof String) {String anotherString = (String) anObject; int n = value. Der Vergleich wird intern mit equals() durchgeführt. "; String s2 = "CodeGym is the best website for learning Java! Let's see one more example to test the equality of string present in the list. Try it Yourself » If the strings are not in the same case (i.e. If all characters are matched, it returns true. Compare Two Strings in Java – equals, compareTo() methods; Search String in Another String in Java – indexOf, lastIndexOf, contains methods; Java Program to Count The Frequency of Each Character in a String; JShell in Java; Wrapper Class in Java; That’s all for the topic Check if a String is Null or Empty in Java. Compare strings to find out if they are equal: String myStr1 = "Hello"; String myStr2 = "Hello"; String myStr3 = "Another String"; System.out.println(myStr1.equals(myStr2)); // Returns true because they are equal System.out.println(myStr1.equals(myStr3)); // false. The Java String equals() method returns true if two strings are equal. This is the definition of lexicographic ordering. String Comparison With String Class. Wenn man eine Klasse erstellt erbt diese die Funktionalität von equals von der Oberklasse bzw. The Java equals() method compares two string objects, the equality operator == compares two strings, and the compareTo() method returns the number difference between two strings. play_arrow. Stringクラスのequalsメ … Since both equals() and == operator are used for comparison so it is necessary to know the differences between these two in order to … We have a list of functions; we can achieve by using that in Java programming language. 378 Java-Tips und Quelltexte für Anfänger letzte Änderung vor 3 Monaten, 27 Tagen, 38 Minuten → String - Strings vergleichen. Wichtig: wenn eine Klasse die Methode equals() überschreibt, muss die Method… See the following section for examples with different possibilities as using the equal Java method. The String equals () method compares the original content of the string. In Java, string equals() method compares the two given strings based on the data / content of the string. ; Since String is immutable, checking the equality of string to another object should be done using equals() method rather than == operator. Java - String equals() Method - This method compares this string to the specified object. Java String equalsIgnoreCase() method is used to compare a string with the method argument object, ignoring case considerations.. These can be letters (lowercase and uppercase), digits, spaces. In Java itself, there are various ways we can check for string equals. Java String equals, equalsIgnoreCase and contentEqualsUse the String equals and equalsIgnoreCase methods. Python “is” operator can be used to efficiently check for the equality of two string objects. String comparison is a crucial part of working with strings in Java. String buffers support mutable strings. The result is zero if the strings are equal; compareTo returns 0 exactly when the equals(Object) method would return true. It compares values of string for equality. As String is one of the most used data types in Java, this is naturally a very commonly used operation. While using W3Schools, you agree to have read and accepted our. "; s2 points to the same place as s1. The String class represents character strings. You could make another 500 identical strings and the result wouldn't change. The equals() is a function that is a case sensitive function. Deshalb muss die equals Methode in vielen Fällen überschriebenwerden. If all characters are not matched then it returns false. © Copyright 2011-2018 www.javatpoint.com. If other string object does not match the same sequence of characters of this object, it returns false. 2. You can check if two strings are equal, by considering case or not considering the case, in your Java application. String Equality. Mail us on hr@javatpoint.com, to get more information about given services. equals () est une méthode utilisée pour comparer deux objets pour l'égalité. On the other hand, equals() method compares whether the value of the strings is equal, and not the object itself. En caso contrario devolverá false. If all the contents of both the strings are same then it returns true. Difference between equals() method and equality operator “==” in Java is asked quite frequently in beginner level Java interviews. upper or lower case), it will be considered as not equal. "; s2 points to the same place as s1. Beide Möglichkeiten ergeben bei mir in einem Test das gleiche Ergebnis (TRUE falls der String identisch ist, FALSE falls nicht). Examples might be simplified to improve reading and learning. Java - String equalsIgnoreCase() Method - This method compares this String to another String, ignoring case considerations. The Java equals() method compares two string objects, the equality operator == compares two strings, and the compareTo() method returns the number difference between two strings. These type of string objects are stored in the heap memory. Determines whether this string and a specified String object have the same value. Java String equals () The java string equals () method compares the two given strings based on the content of the string. Strings sind Objekte. The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object. Using the “==” operator for comparing text values is one of the most common mistakes Java beginners make. Parameters: anObject - The object to compare this String … The is operator returns True if the two variables point to the same data object, else, it returns False.. Syntax: variable1 is variable2 Example: equals. Sie ist in der Klass… String s4 = new String("Genus"); String s5 = new String("Genus"); Here compiler would create two different string objects s4 and s5 in the memory each having the value "Genus". Syntax: public boolean equals (Object anObject) Overrides: equals in Object class. JavaのStringでequalsによる等価判定を行う場合に、 比較対象となる定数は左側にする理由は NullPointerExceptionを回避するため です。 以降、NullPointerExceptionが発生する仕組みと、 定数を左側にすることでどのように回避できるのかについて解説していきます。 目次. The String equals() method overrides the equals() method of Object class. If the argument is null, it returns false e.g. There are three ways to compare strings in Java. Der Datentyp String ist in Java kein einfacher Datentyp wie etwa int oder double oder boolean, sondern eine Klasse.Eine Variable vom Typ String enthält daher nicht den String selbst, sondern sie enthält einen Verweis auf ein Objekt der Klasse String.. If not, equals() returns false. Cannot invoke "String.equalsIgnoreCase(String)" because the return value of "org.bukkit.inventory.meta.ItemMeta.getDisplayName()" is null? "); if (a == b) { System.out.print("Sind gleich! Tip: Use the compareTo() method to compare two strings lexicographically. Duration: 1 week to 2 week. Los. Java String equals () method is used to compare a string with the method argument object. Der Datentyp String ist in Java kein einfacher Datentyp wie etwa int oder double oder boolean, sondern eine Klasse.Eine Variable vom Typ String enthält daher nicht den String selbst, sondern sie enthält einen Verweis auf ein Objekt der Klasse String.. 1. Java ist eine objektorientierte Sprache. "); dot net perls. Möchte man dagegen die lexikalische Gleichheit zweier Strings prüfen, so kann dies u.a. The second statement simply refers to the same area of memory as s1. The Java string equals() method is used to compare objects and check whether the content of two strings are equal. If all characters are not matched then it returns false. Examples. String-Objekte nehmen in Java eine Sonderstellung ein. Syntax: public boolean equals (Object anObject) Overrides: equals in Object class. See the following section for examples with different possibilities as using the equal Java method. In Java, string equals () method compares the two given strings based on the data / content of the string. Two strings are considered equal ignoring case, if they are of the same length Technique 3: Python ‘is’ operator to perform string equals check in python . false false // error: incomparable types: Thread and String .equals() In Java, string equals() method compares the two given strings based on the data/content of the string. If two strings are different, then either they have different characters at some index that is a valid index for both strings, or their lengths are different, or both. 보통 자바에서 equals를 사용하여 문자열이 동일한지 확인합니다.다른 언어와 다르게 ==로 문자열이 같은지 확인하지 않습니다.==는 object가 동일한지를 체크하기 때문에 object가 갖고 있는 문자열이 동일하다는 것을 보장하지 않기 때문입니다. JavaTpoint offers too many high quality services. The java string equals() method compares the two given strings based on the content of the string. Ob ein String mit einem Wort beginnt oder endet, sagen startsWith() und endsWith(). ; String equals() method always return boolean value, it doesn’t throw any exceptions. To compare these strings in Java, we need to use the equals() method of the string. Ein Parameter gibt die Kultur, Berücksichtigung von Groß- und Kleinschreibung und Sortierregeln, die für den Vergleich verwendet werden. If the argument is null, it returns false e.g. Java SE 7 . Difference between == and equals method in Java. Descripción . If all the contents of both the strings are same then it returns true. The result is true if and only if the argument is not null and is a String object that represents the The result is true if and only if the argument is not null and is a String object that represents the The first statement creates a new string in the string pool. All string literals in Java programs, such as "abc", are implemented as instances of this class.. Strings are constant; their values cannot be changed after they are created. Strings sind Objekte. Technique 3: Python ‘is’ operator to perform string equals check in python . The result is true if and only if the argument is not null and is a String object that represents the same sequence of characters as this object. equals. If all characters are not matched then it returns false. In general, we have Java equals() and equalsIgnoreCase() for check the string equality. value; int i = 0; while (n--!= 0) {if (v1 [i]!= v2 [i]) return false; i ++;} return true;}} return false;} String equals() method in java with example: This method compares this string to the specified object. Java String compare. For example java.lang.String class overrides the equals() and hashcode method and in the overridden method, it will check that two string contains same value or character if yes then they are equals otherwise not equal. equals() est une méthode utilisée pour comparer deux objets pour l'égalité. length) {char v1 [] = value; char v2 [] = anotherString. In this tutorial, we shall see how to check if two Strings are equal in Java using the method String.equals(String anotherString). There are three ways to check the equality of two strings in java. String s1 = "CodeGym is the best website for learning Java! Since String is immutable, checking the equality of string to another object should be done using equals () method rather than == operator. 2.1. The String equals () method overrides the equals () method of Object class. String equals() method in java with example: This method compares this string to the specified object. … Der Vergleich wird intern mit equals() durchgeführt. Also, we shall go through an example Java program to ignore the case of the characters in the string, and check if two Strings are equal. All string literals in Java programs, such as "abc", are implemented as instances of this class.. Strings are constant; their values cannot be changed after they are created. Strings contain characters. With equals, we test the chars in two string objects. Example. Einmal mit == und einmal mit .equals(). If any character is not matched, it returns false. Wait a minute. Below example illustrate the use of.equals for string comparison in Java: The String equals method looks at the two Java strings, and if they contain the exact same string of characters, they are considered equal. Ob ein String mit einem Wort beginnt oder endet, sagen startsWith() und endsWith(). The equality operator and null are tested. こんにちは!フリーライターの中井です。 Javaには文字列の比較を行うStringクラスに属するequalsメソッドがあります。この記事では、equalsメソッドについて 「==」と「equals」の違いについて equalsメソッドで否定の判定をする方法 複数の否定の判定をする方法 Führt man jedoch Vergleiche mit lexikalisch identischen String-Objekten durch, so zeigen sich eigenartige Ergebnisse: Der Vergleichsoperator ' == ' dient beim Objektvergleich der Überprüfung der Identität der Objekte selbst, also ihrem Speicherort, nicht einer lexikalischen Übereinstimmung. In this tutorial, you will learn about the Java equals() method with the help of examples. String equals NULL Problem: Java Basics - Anfänger-Themen: 4: 1. Seit Java 7 erlaubt switch den Vergleich von String-Objekten mit einer Liste von Sprungzielen. Java - String equalsIgnoreCase() Method - This method compares this String to another String, ignoring case considerations. Java String equalsIgnoreCase() Method String Methods. In Java scheint man einen String auf zwei verschiedene Arten vergleichen zu können. Please mail your requirement at hr@javatpoint.com. Use equals () method to check the equality of … equals() accepts one parameter: the string you want to compare to another string. "); String b = new String("Hello World!