In JavaScript, the startsWith() and endsWith() methods are used to check whether a string starts or ends with a specific substring, respectively. These methods return a boolean value (true or false) based on whether the condition is met or not. Here's how they work: startsWith(): This method checks if a string starts with the characters of a specified string. const str = 'Hello World'; console.log(str.startsWith('Hello')); // true console.log(str.startsWith('He')); // true console.log(str.startsWith('hello')); // false (case-sensitive) endsWith(): This method checks if a string ends with the characters of a specified string. const str = 'Hello World'; console.log(str.endsWith('World')); // true console.log(str.endsWith('rld')); // true console.log(str.endsWith('world')); // false (case-sensitive)