Java program to check valid Balanced parentheses

Balanced parentheses:

•   A string which contains below characters in correct order.
•  "{}" "[]" "()"
• We need to check whether given string has valid order of parenthesis order.
• If the parenthesis characters are placed in order then we can say its valid parentheses or balanced parentheses.
• If the parentheses characters are not in correct order or open and close then we can say it is not balanced or invalid parenthesis.
• Program to check given string has a valid parenthesis or not.

#1: Java example program to check given string has valid parenthesis or not.

1. package instanceofjava;
2. 
   
3. import java.util.Stack;
4. 
   
5. public class BalancedParenthensies {
6. 
   
7. public static void main(String[] args) {
9. System.out.println(checkParenthensies("{(xxx,yyy)}"));
10. System.out.println(checkParenthensies("{)(acd,bcvfs}"));
11. System.out.println(checkParenthensies("{(xxx},yyy)"));
12. System.out.println(checkParenthensies("[(xxx),yyy]"));
13. }
14. public static boolean checkParenthensies(String str) {
15.         Stack<Character> object  = new Stack<Character>();
16.         for(int i = 0; i < str.length(); i++) {
17.             char ch = str.charAt(i);
18.             if(ch == '[' || ch == '(' || ch == '{' ) {     
19.             object.push(ch);
20.             } else if(ch == ']') {
21.                 if(object.isEmpty() || object.pop() != '[') {
22.                     return false;
23.                 }
24.             } else if(ch == ')') {
25.                 if(object.isEmpty() || object.pop() != '(') {
26.                     return false;
27.                 }           
28.             } else if(ch == '}') {
29.                 if(object.isEmpty() || object.pop() != '{') {
30.                     return false;
31.                 }
32.             }
33.         }
34.         return object.isEmpty();
35.     }
36. }

Output:

1. true
2. false
3. false
4. true