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:

• Using for loop
• Using the while loop
• Using a do-while loop

Program to print (A to Z) and (a to z) using for loop:

In the below program:

• For loop is used to print the alphabets 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

<script>
    // 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));
    }
</script>

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

Program to print (A to Z) and (a to z) using while loop:

In the below program:

• While loop is used to print the alphabets 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

<script>
    // 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++;
    }
</script>

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

Program to print (A to Z) and (a to z) using do-while loop:

In the below program:

• 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

<script>
    // 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);
</script>

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