includes()

• Description: Checks if a string contains a specified value, returning true or false.

• Example:

  let str = 'Hello, World!';
  console.log(str.includes('World')); // Output: true
  
  

indexOf()

• Description: Returns the position of the first occurrence of a specified value in a string.

• Example:

  let str = 'Hello, World!';
  console.log(str.indexOf('World')); // Output: 7
  
  

lastIndexOf()

• Description: Returns the position of the last occurrence of a specified value in a string.

• Example:

  let str = 'Hello, World! Hello!';
  console.log(str.lastIndexOf('Hello')); // Output: 14
  
  

startsWith()

• Description: Checks if a string starts with a specified value.

• Example:

  let str = 'Hello, World!';
  console.log(str.startsWith('Hello')); // Output: true
  
  

endsWith()

• Description: Checks if a string ends with a specified value.

• Example:

  let str = 'Hello, World!';
  console.log(str.endsWith('!')); // Output: true