JavaScript program to print Alphabets from A to Z using Loop

Our task is to print the alphabet from A to Z using loops. In this article, we will mainly focus on the following programs and their logic.

Below are the loops used to print Alphabets from A to Z:

Using for loop

The elements are iterated through a predetermined number of times in the JavaScript for a loop.

• For loop is used to print the alphabet from A to Z. A loop variable is taken to do this of type ‘char’. 
• The loop variable ‘i’ is initialized with the first alphabet ‘A’ and incremented by 1 on every iteration.
• In the loop, the character ‘i’ is printed as the alphabet.

Example: Below is the example that will print (A to Z) and (a to z) using for loop:

Javascript

// Declaring Variables
let i;

console.log("Alphabets form (A-Z) are:");

// Using for loop for (A-Z):
for (i = 65; i <= 90; i++) {
    console.log(String.fromCharCode(i));
}

console.log("Alphabets from (a-z) are:");

// Using for loop for (a-z):
for (i = 97; i <= 122; i++) {
    console.log(String.fromCharCode(i));
}

Output:

Alphabets form (A-Z) are:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Alphabets from (a-z) are:
a b c d e f g h i j k l m n o p q r s t u v w x y z

Using the while loop

The element is iterated an infinite number of times. if a number of iterations are not given. 

• While loop is used to print the alphabet from A to Z. A loop variable is taken to display of type ‘char’. 
• The loop variable ‘i’ is initialized with the first alphabet ‘A’ and incremented by 1 on every iteration.
• In the loop, the character ‘i’ is printed as the alphabet.

Example: Below is the example that will print (A to Z) and (a to z) using for while loop.

Javascript

// Declaring Variables
let i;

// Initializing i = 65 for Uppercase:
i = 65;
console.log("Alphabets form (A-Z) are:");

while (i <= 90) {
    console.log(String.fromCharCode(i));
    i++;
}

i = 97;
console.log("Alphabets from (a-z) are:");

while (i <= 122) {
    console.log(String.fromCharCode(i));
    i++;
}

Output:

Alphabets form (A-Z) are:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Alphabets from (a-z) are:
a b c d e f g h i j k l m n o p q r s t u v w x y z

Using a do-while loop

Similar to a while loop iterates the element an infinite of times .however whether the condition is true or false, the code is always run at least once.

• The do-while loop is used to print the alphabet from A to Z. A loop variable is taken to display of type ‘char’. 
• The loop variable ‘i’ is initialized with the first alphabet ‘A’ and incremented by 1 on every iteration.
• In the loop, the character ‘i’ is printed as the alphabet.

Example: Below is the example that will print (A to Z) and (a to z) using for do-while loop.

Javascript

// Declaring Variables
let i;

// Initializing i = 65 for Uppercase:
i = 65;
console.log("Alphabets form (A-Z) are:");

do {
    console.log(String.fromCharCode(i));
    i++;
} while (i <= 90);

i = 97;
console.log("Alphabets from (a-z) are:");

do {
    console.log(String.fromCharCode(i));
    i++;
} while (i <= 122);

Output:

Alphabets form (A-Z) are:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Alphabets from (a-z) are:
a b c d e f g h i j k l m n o p q r s t u v w x y z