concat()

• Description: Combines the text of two or more strings and returns a new string.

• Example:

  let str1 = 'Hello';
  let str2 = 'World';
  let result = str1.concat(', ', str2);
  console.log(result); // Output: 'Hello, World'
  
  

replace()

• Description: Searches a string for a specified value, or a regular expression, and returns a new string with the specified values replaced.

• Example:

  let str = 'Hello, World!';
  let newStr = str.replace('World', 'JavaScript');
  console.log(newStr); // Output: 'Hello, JavaScript!'
  
  

split()

• Description: Splits a string into an array of substrings, and returns the new array.

• Example:

  let str = 'Hello, World!';
  let arr = str.split(', ');
  console.log(arr); // Output: ['Hello', 'World!']
  
  

substring()

• Description: Extracts the characters from a string, between two specified indices, and returns the new substring.

• Example:

  let str = 'Hello, World!';
  let substr = str.substring(0, 5);
  console.log(substr); // Output: 'Hello'