In this article, we will discuss how to swap 2 String variables using third variables and without using 3rd variable
Swapping 2 String variables:
- Without using third String variable
- Using third String variable
1. Swapping 2 Strings w/o using Third Variable
- First, concatenate 2 Strings (str1 + str2) and assign it to 1st String variable (str1) using + (plus) operator
- Next, get sub-string from the concatenated String from 0th index till difference of 2 Strings length and assign it to 2nd String str2
- Finally, get another sub-string from the concatenated String starting from length of new assigned String str2 till the end
- We will print both String before & after swapping String variables
SwapTwoStringsWithoutThirdVariable.java
package in.bench.resources.string.operation;
public class SwapTwoStringsWithoutThirdVariable {
public static void main(String[] args) {
// String variables
String str1 = "Java";
String str2 = "World";
// print before swapping
System.out.println("Before swapping 2 Strings :- ");
System.out.println("String 1 = " + str1);
System.out.println("String 2 = " + str2);
// concatenate 2 Strings
str1 = str1 + str2; // 4 + 5 = 9
// swap 1st String using String.substring(start, end)
str2 = str1.substring(0, str1.length() - str2.length()); // 0, 9
// swap 2nd String using String.substring(start)
str1 = str1.substring(str2.length()); // 4
// print after swapping
System.out.println("\n\nAfter swapping 2 Strings :- ");
System.out.println("String 1 = " + str1);
System.out.println("String 2 = " + str2);
}
}
Output:
Before swapping 2 Strings :-
String 1 = Java
String 2 = World
After swapping 2 Strings :-
String 1 = World
String 2 = Java
2. Swapping 2 Strings using Third Variable
- Declare a temp variable
- First, assign 1st String value to temp variable
- Second, assign 2nd String value to 1st String variable
- Third, assign temp String value to 2nd String variable
- We will print both String before & after swapping String variables
SwapTwoStrings.java
package in.bench.resources.string.operation;
public class SwapTwoStrings {
public static void main(String[] args) {
// String variables
String str1 = "Java";
String str2 = "World";
String temp = null;
// print before swapping
System.out.println("Before swapping 2 Strings :- ");
System.out.println("String 1 = " + str1);
System.out.println("String 2 = " + str2);
// swapping using temp variable
temp = str1;
str1 = str2;
str2 = temp;
// print after swapping
System.out.println("\n\nAfter swapping 2 Strings :- ");
System.out.println("String 1 = " + str1);
System.out.println("String 2 = " + str2);
}
}
Output:
Before swapping 2 Strings :-
String 1 = Java
String 2 = World
After swapping 2 Strings :-
String 1 = World
String 2 = Java
Happy Coding !!
Happy Learning !!
