Compare two string value « String « Character String « Development

Return	Method	Summary
int	compareTo(String anotherString)	Compares two strings lexicographically.
int	compareToIgnoreCase(String str)	Compares two strings lexicographically, ignoring case differences.
boolean	equals(Object anObject)	Compares this string to the specified object.
boolean	equalsIgnoreCase(String anotherString)	Compares this String to another String, ignoring case considerations.

The result of the compareTo(String anotherString) and compareToIgnoreCase(String str) is shown here:

Value	Meaning
Less than zero	The invoking string is less than str.
Greater than zero	The invoking string is greater than str.
Zero	The two strings are equal.


public class Main {
  public static void main(String[] argv) {
    String str = "Java2s.com";
    String str2 = "java2s.com";
    System.out.println(str.compareTo(str2));
    System.out.println(str.compareToIgnoreCase(str2));

  }
}


-32
0

compareToIgnoreCase(String str) returns the same results as compareTo( ). It only ignores the case differences.


public class Main {

  public static void main(String args[]) {
    System.out.println("A".compareToIgnoreCase("a"));
  }
}

The following code checks the length of a string, then gets the fourth char out of the string object and compares these two string objects.


public class Main {
  public static void main(String args[]) {
    String strOb1 = "java2s.com";
    String strOb2 = "java2s.com";
    String strOb3 = strOb1;

    System.out.println("Length of strOb1: " + strOb1.length());
    System.out.println("Char at index 3 in strOb1: " + strOb1.charAt(3));

    if (strOb1.equals(strOb2))
      System.out.println("strOb1 == strOb2");
    else
      System.out.println("strOb1 != strOb2");

    if (strOb1.equals(strOb3))
      System.out.println("strOb1 == strOb3");
    else
      System.out.println("strOb1 != strOb3");
  }
}


Length of strOb1: 10
Char at index 3 in strOb1: a
strOb1 == strOb2
strOb1 == strOb3


public class Main {
  public static void main(String args[]) {
    String s1 = "Hello";
    String s2 = "Hello";
    String s3 = "Good-bye";
    String s4 = "HELLO";
    System.out.println(s1 + " equals " + s2 + " -> " +

    s1.equals(s2));
    System.out.println(s1 + " equals " + s3 + " -> " + s1.equals(s3));
    System.out.println(s1 + " equals " + s4 + " -> " + s1.equals(s4));
    System.out.println(s1 + " equalsIgnoreCase " + s4 + " -> " + s1.equalsIgnoreCase(s4));
  }
}



Hello equals Hello -> true
Hello equals Good-bye -> false
Hello equals HELLO -> false
Hello equalsIgnoreCase HELLO -> true


boolean equalsIgnoreCase(String str)

str is the String object being compared with the invoking String object. Here is an example that demonstrates equals( ) and equalsIgnoreCase( ):


public class Main {
  public static void main(String args[]) {
    String s1 = "Hello";
    String s2 = "Hello";
    String s3 = "Good-bye";
    String s4 = "HELLO";
    System.out.println(s1 + " equals " + s2 + " -> " +

    s1.equals(s2));
    System.out.println(s1 + " equals " + s3 + " -> " + s1.equals(s3));
    System.out.println(s1 + " equals " + s4 + " -> " + s1.equals(s4));
    System.out.println(s1 + " equalsIgnoreCase " + s4 + " -> " + s1.equalsIgnoreCase(s4));
  }
}


Hello equals Hello -> true
Hello equals Good-bye -> false
Hello equals HELLO -> false
Hello equalsIgnoreCase HELLO -> true