Java Program to Toggle All Characters in a String

Write a Java Program to Toggle All Character cases in a String with an example. In this toggle Uppercase to Lowercase & Lowercase to Upper example, we used for loop to iterate StrToToggle. Inside the loop, we used the Else If statement. 

Within the first if condition, we used isUpperCase ( (Character.isUpperCase (StrToToggle.charAt(i))) to check the character at the index position is uppercase. If True, we used the toLowerCase ( Character.toLowerCase( StrToToggle.charAt(i) ) to convert it to a lowercase character.

Next, we used isLowerCase() ( Character.isLowerCase( StrToToggle.charAt(i))) to check the character is lowercase. If True, we used the toUpperCase() ( Character.toUpperCase ( StrToToggle.charAt(i)) ) to convert it to the uppercase character.

import java.util.Scanner;

public class ToggleCharsinStr1 {
	private static Scanner sc;
	public static void main(String[] args) {
		String StrToToggle, tCaseStr = "";
		
		sc= new Scanner(System.in);

		System.out.print("\nEnter Any String to Toggle Case =  ");
		StrToToggle = sc.nextLine();
				
		for(int i = 0; i < StrToToggle.length(); i++)  {
			if(Character.isUpperCase(StrToToggle.charAt(i)))  {
				tCaseStr +=  Character.toLowerCase(StrToToggle.charAt(i));
			}
			else if(Character.isLowerCase(StrToToggle.charAt(i))) {
				tCaseStr +=  Character.toUpperCase(StrToToggle.charAt(i));
			}
			else {
				tCaseStr += StrToToggle.charAt(i);
			}
		}

		System.out.println("\nThe Final String after Toggling all Characters =  " + tCaseStr);
	}
}

In this toggle character case of a string example, we first converted the StrToToggle string to the CharArrToToggle character array using the toCharArray(). 

Within the loop, we check whether the character at index position CharArrToToggle[i] is greater than or equal to a and less than or equal to z. If it is true, we are subtracting 32 from the current ASCII value. Next, we check the character is greater than or equal to A and less than or equal to Z. If it is True, we are adding 32 to the current ASCII value. For example, A = 65, after adding 32, it becomes 97, and the ASCII value of a = 97.

import java.util.Scanner;

public class ToggleCharsinStr2 {
	private static Scanner sc;
	public static void main(String[] args) {
		String StrToToggle;
		
		sc= new Scanner(System.in);

		System.out.print("\nEnter Any String to Toggle Case =  ");
		StrToToggle = sc.nextLine();
		
		char[] CharArrToToggle = StrToToggle.toCharArray();
		
		for(int i = 0; i < CharArrToToggle.length; i++)
		{
			if(CharArrToToggle[i] >= 'a' && CharArrToToggle[i] <= 'z') {
				CharArrToToggle[i] = (char) ((int)CharArrToToggle[i] - 32);;
			}			
			else if(CharArrToToggle[i] >= 'A' && CharArrToToggle[i] <= 'Z') {
				CharArrToToggle[i] = (char) ((int)CharArrToToggle[i] + 32);;
			}
		}
		System.out.println("\nThe Final String after Toggling all Characters =  ");
		System.out.print(CharArrToToggle);
	}
}

Toggle string character cases output

Enter Any String to Toggle Case =  JavaProgrAMS

The Final String after Toggling all Characters =  
jAVApROGRams

Java Program to Toggle All Characters in a String Example 3

Here, we declared an empty character and assigned the case converted character to ch. Then, we set each character to tCaseStr.

import java.util.Scanner;

public class ToggleCharsinStr3 {
	private static Scanner sc;
	public static void main(String[] args) {
		String StrToToggle, tCaseStr = "";
		
		sc= new Scanner(System.in);

		System.out.print("\nEnter Any String to Toggle Case =  ");
		StrToToggle = sc.nextLine();
		
		char ch = '\0';
		for(int i = 0; i < StrToToggle.length(); i++)
		{
			if(StrToToggle.charAt(i) >= 'a' && StrToToggle.charAt(i) <= 'z') {
				ch = (char) (StrToToggle.charAt(i) - 32);
			}			
			else if(StrToToggle.charAt(i) >= 'A' && StrToToggle.charAt(i) <= 'Z') {
				ch = (char) (StrToToggle.charAt(i) + 32);
			}
			else {
				ch = StrToToggle.charAt(i);
			}
			tCaseStr += ch;
		}
		System.out.println("\nThe Final String after Toggling all Characters =  " + tCaseStr);
	}
}

Toggle string characters cases output

Enter Any String to Toggle Case =  TutoRIAl GateWAy

The Final String after Toggling all Characters =  
tUTOriaL gATEwaY

In this code, to toggle all character cases in a String, we are comparing the ASCII values instead of comparing characters.

import java.util.Scanner;

public class ToggleCharsinStr4 {
	private static Scanner sc;
	public static void main(String[] args) {
		String StrToToggle, tCaseStr = "";
		
		sc= new Scanner(System.in);

		System.out.print("\nEnter Any String =  ");
		StrToToggle = sc.nextLine();
		
		char ch = '\0';
		for(int i = 0; i < StrToToggle.length(); i++)
		{
			if(StrToToggle.charAt(i) >= 65 && StrToToggle.charAt(i) <= 90) {
				ch = (char) (StrToToggle.charAt(i) + 32);
			}			
			else if(StrToToggle.charAt(i) >= 97 && StrToToggle.charAt(i) <= 122) {
				ch = (char) (StrToToggle.charAt(i) - 32);
			}
			else {
				ch = StrToToggle.charAt(i);
			}
			tCaseStr += ch;
		}
		System.out.println("\nThe Final String after Toggling all Characters =  " + tCaseStr);
	}
}

Enter Any String =  HappY coDINg

The Final String after Toggling all Characters =  hAPPy COdinG

This Java program for toggle string character cases, we converted the string CharArrToToggle. And the remaining is the same as the above.

import java.util.Scanner;

public class ToggleCharsinStr5 {
	private static Scanner sc;
	public static void main(String[] args) {
		String StrToToggle;
		
		sc= new Scanner(System.in);

		System.out.print("\nEnter Any String =  ");
		StrToToggle = sc.nextLine();
		
		char[] CharArrToToggle = StrToToggle.toCharArray();
		
		for(int i = 0; i < CharArrToToggle.length; i++)
		{
			if(CharArrToToggle[i] >= 65 && CharArrToToggle[i] <= 90) {
				CharArrToToggle[i] = (char) ((int)CharArrToToggle[i] + 32);;
			}			
			else if(CharArrToToggle[i] >= 97 && CharArrToToggle[i] <= 122) {
				CharArrToToggle[i] = (char) ((int)CharArrToToggle[i] - 32);;
			}
		}
		System.out.println("\nThe Final String after Toggling all Characters =  ");
		System.out.print(CharArrToToggle);
	}
}

Toggle characters output

Enter Any String =  TogglE CharaCTERs

The Final String after Toggling all Characters =  
tOGGLe cHARActerS

It is another Java example to toggle string character cases.

import java.util.Scanner;

public class ToggleCharsinStr6 {
	private static Scanner sc;
	public static void main(String[] args) {
		String StrToTog;
		
		sc= new Scanner(System.in);

		System.out.print("\nEnter Any Text =  ");
		StrToTog = sc.nextLine();
		
		char[] CharArrToTog = StrToTog.toCharArray();
		
		for(int i = 0; i < CharArrToTog.length; i++)
		{
			if(CharArrToTog[i] >= 'a' && CharArrToTog[i] <= 'z') {
				CharArrToTog[i] = (char) ((int)CharArrToTog[i] + 'A' - 'a');;
			}			
			else if(CharArrToTog[i] >= 'A' && CharArrToTog[i] <= 'Z') {
				CharArrToTog[i] = (char) ((int)CharArrToTog[i] + 'a' - 'A');;
			}
		}
		System.out.println("\nThe Final String after Toggling all Characters =  " );
		System.out.print(CharArrToTog);
	}
}

Enter Any Text =  Hello224 Java PROGRammErs!

The Final String after Toggling all Characters =  
hELLO224 jAVA progrAMMeRS!