String Length

Program to find length of a string

BeginnerTopic: String Programs

JavaScript String Length Program

This program helps you to learn the fundamental structure and syntax of JavaScript programming.

// Method 1: Using length property
let str = "Hello World";
console.log("String:", str);
console.log("Length:", str.length);

// Method 2: Manual count using loop
function stringLength(str) {
    let count = 0;
    for (let i = 0; i < str.length; i++) {
        count++;
    }
    return count;
}

console.log("\nManual count:", stringLength("JavaScript"));

// Method 3: Using split and length
function stringLengthSplit(str) {
    return str.split('').length;
}

console.log("Using split:", stringLengthSplit("Programming"));

// Method 4: Count without spaces
function stringLengthNoSpaces(str) {
    return str.replace(/\s/g, '').length;
}

console.log("\nLength without spaces:", stringLengthNoSpaces("Hello World"));

// Method 5: Count words
function countWords(str) {
    return str.trim().split(/\s+/).length;
}

console.log("Word count:", countWords("Hello World from JavaScript"));

Output

String: Hello World
Length: 11

Manual count: 10

Using split: 11

Length without spaces: 10

Word count: 4

Understanding String Length

This program demonstrates different ways to find string length.

Method 1: Length Property

Built-in property:

str.length;

Returns:

Number of characters (including spaces)

Method 2: Manual Count

Using loop:

let count = 0;
for (let i = 0; i < str.length; i++) {
    count++;
}

Method 3: Split and Length

Convert to array:

str.split('').length;

Split Method:

•Converts string to array

•Each character becomes array element

Method 4: Length Without Spaces

Remove spaces first:

str.replace(/\s/g, '').length;

Regular Expression:

•/\s/g: Matches all whitespace

•g: Global flag (all occurrences)

Method 5: Word Count

Count words, not characters:

str.trim().split(/\s+/).length;

String Methods:

•trim(): Removes leading/trailing spaces

•split(/\s+/): Splits on one or more spaces

Important Notes:

•length is a property, not a method

•Returns number of UTF-16 code units

•Special characters may count as 2

When to Use:

length property

: Standard, fastest

Manual count

: Learning

Split

: When you need array anyway

Let us now understand every line and the components of the above program.

Note: To write and run JavaScript programs, you need to set up the local environment on your computer. Refer to the complete article Setting up JavaScript Development Environment. If you do not want to set up the local environment on your computer, you can also use online IDE to write and run your JavaScript programs.

Practical Learning Notes for String Length

This JavaScript program is part of the "String Programs" topic and is designed to help you build real problem-solving confidence, not just memorize syntax. Start by understanding the goal of the program in plain language, then trace the logic line by line with a custom input of your own. Once you can predict the output before running the code, your understanding becomes much stronger.

A reliable practice pattern is to run the original version first, then modify only one condition or variable at a time. Observe how that single change affects control flow and output. This deliberate style helps you understand loops, conditions, and data movement much faster than copying full solutions repeatedly.

For interview preparation, explain this solution in three layers: the high-level approach, the step-by-step execution, and the time-space tradeoff. If you can teach these three layers clearly, you are ready to solve close variations of this problem under time pressure.

Reverse a String