Java String equals() Method
Java String ClassThe equals() method is used to compare a string with the specified object.
The equals() method is overridden in the String class to compare whether the contents of two strings are equal.
Syntax
public boolean equals(Object anObject)
Parameters
anObject-- The object to compare with the string.
Return Value
Returns true if the given object is equal to the string; otherwise returns false.
Example
Example
public class Test {
public static void main(String args[]) {
String Str1 = new String("example");
String Str2 = Str1;
String Str3 = new String("example");
boolean retVal;
retVal = Str1.equals( Str2 );
System.out.println("Return value = " + retVal );
retVal = Str1.equals( Str3 );
System.out.println("Return value = " + retVal );
}
}
public static void main(String args[]) {
String Str1 = new String("example");
String Str2 = Str1;
String Str3 = new String("example");
boolean retVal;
retVal = Str1.equals( Str2 );
System.out.println("Return value = " + retVal );
retVal = Str1.equals( Str3 );
System.out.println("Return value = " + retVal );
}
}
The output of the above program is:
返回值 = true 返回值 = true
Use==andequals()Compare strings.
In String,==== compares whether the reference addresses are the same,equals()equals compares whether the contents of the strings are the same:
String s1 = "Hello"; // String created directly
String s2 = "Hello"; // String created directly
String s3 = s1; // Same reference
String s4 = new String("Hello"); // String object created
String s5 = new String("Hello"); // String object created
s1 == s1; // true, same reference
s1 == s2; // true, s1 and s2 are both in the public pool, same reference
s1 == s3; // true, s3 has the same reference as s1
s1 == s4; // false, different reference addresses
s4 == s5; // false, different reference addresses in the heap
s1.equals(s3); // true, same content
s1.equals(s4); // true, same content
s4.equals(s5); // true, same content
String s2 = "Hello"; // String created directly
String s3 = s1; // Same reference
String s4 = new String("Hello"); // String object created
String s5 = new String("Hello"); // String object created
s1 == s1; // true, same reference
s1 == s2; // true, s1 and s2 are both in the public pool, same reference
s1 == s3; // true, s3 has the same reference as s1
s1 == s4; // false, different reference addresses
s4 == s5; // false, different reference addresses in the heap
s1.equals(s3); // true, same content
s1.equals(s4); // true, same content
s4.equals(s5); // true, same content
Other Extensions