I have two Strings: str1 and str2. How to check if str2 is contained within str1? You can definitely use Java’s own .contains() method.
Here by this program we will implement contains() method. Let’s call it as findMe(String subString, String mainString) . Find below implementation.
|
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 |
package com.crunchify.tutorials; /** * @author Crunchify.com */ public class CrunchifyFindString { public static void main(String[] args) { System.out.println("\nResult = " + findMe(" findMe", "Can you findMe from this String?")); } public static boolean findMe(String subString, String mainString) { boolean foundme = false; int max = mainString.length() - subString.length(); // Java's Default "contains()" Method System.out.println(mainString.contains(subString) ? "mainString.contains(subString) Check Passed.." : "mainString.contains(subString) Check Failed.."); // Implement your own Contains Method with Recursion checkrecusion: for (int i = 0; i <= max; i++) { int n = subString.length(); int j = i; int k = 0; while (n-- != 0) { if (mainString.charAt(j++) != subString.charAt(k++)) { continue checkrecusion; } } foundme = true; break checkrecusion; } System.out .println(foundme ? "\nImplement your own Contains() Method - Result: Yes, Match Found.." : "\nImplement your own Contains() Method - Result: Nope - No Match Found.."); return foundme; } } |
Result1:
|
1 2 3 4 5 |
mainString.contains(subString) Check Passed.. Implement your own Contains() method - Result: Yes, Match Found.. Result = true |
Result2: (notice blank space between find and Me)
|
1 2 3 4 5 |
mainString.contains(subString) Check Failed.. Implement your own Contains() Method - Result: Nope - No Match Found.. Result = false |
Let me know if you know any better way to implement this.
