Java – String compareToIgnoreCase() Method example

The method compareToIgnoreCase() is similar to the compareTo() method as it also compares two strings lexicographically. The only difference between them is that compareToIgnoreCase() ignores the case (uppercase or lowercase) while comparing two strings. Similar to compareTo() this method also compares the strings based on the Unicode value of their each character. It returns 0 when the strings are equal else it returns positive or negative value.

int compareToIgnoreCase(String str)

Example

In the below example we have three String literals which have same value but the case is different. string1 is in uppercase, string2 is in lowercase and string3 is a mix of uppercase and lowercase. We are using compareToIgnoreCase() method to compare these strings.

public class CompareExample {
   public static void main(String args[]) {
       String string1 = "HELLO";
       String string2 = "hello";
       String string3 = "Hello";

       int var1 = string1.compareToIgnoreCase(string2);
       System.out.println("string1 and string2 comparison: "+var1);

       int var2 = string1.compareToIgnoreCase(string3);
       System.out.println("string1 and string3 comparison: "+var2);

       int var3 = string1.compareToIgnoreCase("HeLLo");
       System.out.println("string1 and HeLLo comparison: "+var3);
   }
}

Output:

string1 and string2 comparison: 0
string1 and string3 comparison: 0
string1 and HeLLo comparison: 0