Unraveling the Power of JavaScript Strings

The includes() Method: A Case-Sensitive Search

The includes() method is a powerful tool for determining whether a string contains a specific set of characters. When combined with an if...else statement, it becomes a potent way to check for the presence of a substring.

let str = "Hello, World!";
if (str.includes("World")) {
  console.log("The string contains 'World'.");
} else {
  console.log("The string does not contain 'World'.");
}

Note that the includes() method is case-sensitive, meaning “fun” and “Fun” are treated as distinct strings.

The indexOf() Method: Finding the Needle in the Haystack

The indexOf() method takes a different approach to searching for substrings. It returns the position of the first occurrence of the specified string, or -1 if it’s not found. This method can be used in conjunction with an if...else statement to check for the presence of a substring, like so:

let str = "Hello, World!";
if (str.indexOf("World")!== -1) {
  console.log("The string contains 'World'.");
} else {
  console.log("The string does not contain 'World'.");
}

Similar to includes(), the indexOf() method is also case-sensitive.

Mastering String Manipulation

By harnessing the power of includes() and indexOf(), you’ll be well on your way to becoming a JavaScript string manipulation master. Whether you’re checking for the presence of a substring or searching for a specific pattern, these methods will help you achieve your goals.

• Checking for the presence of a substring
• Searching for a specific pattern

Remember to keep in mind the case-sensitivity of these methods to ensure accurate results in your JavaScript applications.