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 Java 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 Java 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 o z. If it is true, we are subtracting 32 to the current ASCII value. Next, we check the character is greater than or equal to A and less than or equal o 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!