Objective– Given two strings, find out if they are equal or not without using any built-in function (without using equals() function in java).
Example:
String x='tutorial' and String y='tutorial' are equal - true String x='tutorial' and String y='tutorial ' are equal - false String x='tutorial' and String y=' ' are equal – false
Approach:
- If any of the string is null, return false.
- If lengths of both strings are not matching, return false.
- Check if all the characters of both strings are matching, if not return false.
- If all the steps above got executed without returning false then return true.
Code:
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| public class CompareStrings { | |
| public static boolean compare(String x, String y){ | |
| if(x==null || y==null){ | |
| return false; | |
| } | |
| //compare lengths | |
| if(x.length()!=y.length()) | |
| return false; | |
| //compare all characters | |
| for (int i = 0; i <x.length() ; i++) { | |
| if(x.charAt(i)!=y.charAt(i)) | |
| return false; | |
| } | |
| //if here, means both strings are equal | |
| return true; | |
| } | |
| public static void main(String[] args) { | |
| String x = "tutorial"; | |
| String y = "tutorial"; | |
| System.out.println("String x='" + x + "' and String y='" + y + "' are equal?? –" + compare(x, y)); | |
| x = "tutorial"; | |
| y = "tutorial "; | |
| System.out.println("String x='" + x + "' and String y='" + y + "' are equal?? –" + compare(x, y)); | |
| x = "tutorial"; | |
| y = " "; | |
| System.out.println("String x='" + x + "' and String y='" + y + "' are equal?? –" + compare(x, y)); | |
| } | |
| } |
Output:
String x='tutorial' and String y='tutorial' are equal?? -true String x='tutorial' and String y='tutorial ' are equal?? -false String x='tutorial' and String y=' ' are equal?? -false