Java Program to compare two string.
Objective
Write a Java program to compare two strings to see if they are identical.
Algorithm / Approach
- Read two strings from the user and store them in
s1ands2. - Use the
equals()method in anifcondition:if(s1.equals(s2)). - If it returns true, print "SAME STRING".
- Otherwise, print "DIFFERENT STRING".
Test.java
import java.util.Scanner;
class Test {
public static void main(String[] a)
{
Scanner s=new Scanner(System.in);
System.out.print("Enter 1st String: ");
String s1 = s.nextLine();
System.out.print("Enter 2nd String: ");
String s2 = s.nextLine();
if(s1.equals(s2)) {
System.out.print("SAME STRING");
}
else {
System.out.print("DIFFERENT STRING");
}
}
}Expected Output
Enter 1st String: java prowess Enter 2nd String: c++ prowess DIFFERENT STRING
Explanation of the Program
- In Java, you should NEVER use the
==operator to compare the actual text of two strings. The==operator checks if both variables point to the exact same memory location, not if their text is the same. - The
equals()method strictly compares the characters inside the strings for an exact match, including case sensitivity. - If you wanted to ignore case sensitivity, you would use
equalsIgnoreCase()instead.
Complexity
Time Complexity
O(n) - Checks characters one by one until a mismatch is found.
Space Complexity
O(1)
