JavaScript - startsWith() method

revision:

Category : string

The startsWith() method returns true if a string starts with a specified string. Otherwise it returns false. The startsWith() method is case-sensitive.

Syntax : 

        string.startsWith(searchvalue, start)

Parameters:

searchvalue : required. The string to search for.

start : optional. Start position. Default value is 0.

Examples:

            <p>startsWith() returns true if a string starts with a specified string:</p>
            <p id="demo"></p>
            <script>
                let text = "Hello world, welcome to the universe.";
                let result = text.startsWith("Hello");
                document.getElementById("demo").innerHTML = result;
            </script>

Practical examples

example: check if a string starts with "...".

code: 
                    <div>
                        <p id="start-1"></p>
                        <p id="start-2"></p>
                        <p id="start-3"></p>
                        <p id="start-4"></p>
                        <p id="start-5"></p>
                    </div>
                    <script>
                        let text = "Hello world, welcome to the universe.";
                        document.getElementById("start-1").innerHTML = "string : " + text;
                        let result = text.startsWith("Hello");
                        document.getElementById("start-2").innerHTML = "starts with 'Hello' = " + result;
                        let result1 = text.startsWith("Hello", 1);
                        document.getElementById("start-3").innerHTML = "starts with 'Hello' = " + result1;
                        document.getElementById("start-4").innerHTML = "starts with 'Hello' = " + text.startsWith("Hello", 0);
                        
                    </script>