Java String equals()

The Java String class equals() method compares the two given strings based on the content of the string. If any character is not matched, it returns false. If all characters are matched, it returns true.

The String equals() method overrides the equals() method of the Object class.

Signature

Parameter

anotherObject : another object, i.e., compared with this string.

Returns

true if characters of both strings are equal otherwise false.

Internal implementation

  public boolean equals(Object anObject) {          if (this == anObject) {              return true;          }          if (anObject instanceof String) {              String anotherString = (String) anObject;              int n = value.length;              if (n == anotherString.value.length) {                  char v1[] = value;                  char v2[] = anotherString.value;                  int i = 0;                  while (n– != 0) {                      if (v1[i] != v2[i])                              return false;                      i++;                  }                  return true;              }          }          return false;      }    

Java String equals() Method Example

FileName: EqualsExample.java

  public class EqualsExample{  public static void main(String args[]){  String s1=”tutoraspire”;  String s2=”tutoraspire”;  String s3=”TUTORASPIRE”;  String s4=”python”;  System.out.println(s1.equals(s2));//true because content and case is same  System.out.println(s1.equals(s3));//false because case is not same  System.out.println(s1.equals(s4));//false because content is not same  }}  

Test it Now

Output:

true  false  false

Java String equals() Method Example 2

The equals() method compares two strings and can be used in if-else control structure.

FileName: EqualsExample2.java

  public class EqualsExample2 {  public static void main(String[] args) {  String s1 = “tutoraspire”;    String s2 = “tutoraspire”;    String s3 = “Tutoraspire”;  System.out.println(s1.equals(s2)); // True because content is same    if (s1.equals(s3)) {  System.out.println(“both strings are equal”);  }else System.out.println(“both strings are unequal”);  }  }  

Output:

true  both strings are unequal

Java String equals() Method Example 3

Let’s see one more example to test the equality of string present in the list.

FileName: EqualsExample3.java

  import java.util.ArrayList;  public class EqualsExample3 {  public static void main(String[] args) {  String str1 = “Mukesh”;  ArrayList list = new ArrayList<>();  list.add(“Ravi”);   list.add(“Mukesh”);  list.add(“Ramesh”);  list.add(“Ajay”);  for (String str : list) {  if (str.equals(str1)) {  System.out.println(“Mukesh is present”);  }  }  }  }  

Output:

Mukesh is present

Java String equals() Method Example 4

The internal implementation of the equals() method shows that one can pass the reference of any object in the parameter of the method. The following example shows the same.

FileName: EqualsExample4.java

  public class EqualsExample4   {  // main method  public static void main(String argvs[])  {  // Strings  String str = “a”;  String str1 = “123”;  String str2 = “45.89”;  String str3 = “false”;  Character c = new Character(‘a’);  Integer i = new Integer(123);  Float f = new Float(45.89);  Boolean b = new Boolean(false);  // reference of the Character object is passed  System.out.println(str.equals(c));  // reference of the Integer object is passed  System.out.println(str1.equals(i));  // reference of the Float object is passed  System.out.println(str2.equals(f));  // reference of the Boolean object is passed  System.out.println(str3.equals(b));  // the above print statements show a false value because  // we are comparing a String with different data types  // To achieve the true value, we have to convert   // the different data types into the string using the toString() method  System.out.println(str.equals(c.toString()));  System.out.println(str1.equals(i.toString()));  System.out.println(str2.equals(f.toString()));  System.out.println(str3.equals(b.toString()));  }  }  

Output:

false  false  false  false  true  true  true  true

Next TopicJava String equalsIgnoreCase()

equals()equalsignorecase example java method signature string

Java String equals() method

Java String equals()

Signature

Parameter

Returns

Internal implementation

Java String equals() Method Example

Java String equals() Method Example 2

Java String equals() Method Example 3

Java String equals() Method Example 4

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