In JavaScript, there is a built-in method called “slice()” that allows you to extract a portion of a string. This method is useful when you want to retrieve a specific substring from a larger string.

The syntax for using the slice method is as follows:

string.slice(startIndex, endIndex)

• string: This is the original string from which you want to extract a substring.
• startIndex: This is the starting index of the substring you want to extract. The character at this index will be included in the extracted substring.
• endIndex: This is the ending index of the substring you want to extract. The character at this index will not be included in the extracted substring.

Keep in mind that the slice method returns a new string and does not modify the original string.

Let’s look at a few examples to better understand how to use the slice method:

Example 1: Extracting a substring from the beginning of a string

const originalString = "Hello, World!";
const extractedSubstring = originalString.slice(0, 5);

console.log(extractedSubstring); // Output: "Hello"

In this example, we are extracting the substring “Hello” from the beginning of the original string by specifying the start index as 0 and the end index as 5.

Example 2: Extracting a substring from the middle of a string

const originalString = "Hello, World!";
const extractedSubstring = originalString.slice(7, 12);

console.log(extractedSubstring); // Output: "World"

In this example, we are extracting the substring “World” from the middle of the original string by specifying the start index as 7 and the end index as 12.

Example 3: Extracting a substring using negative indices

const originalString = "Hello, World!";
const extractedSubstring = originalString.slice(-6, -1);

console.log(extractedSubstring); // Output: "World"

In this example, we are using negative indices to extract the substring “World” from the end of the original string. The start index of -6 corresponds to the letter “W” and the end index of -1 corresponds to the letter “d”.

Example 4: Extracting the last character of a string

const originalString = "Hello, World!";
const extractedSubstring = originalString.slice(-1);

console.log(extractedSubstring); // Output: "!"

In this example, we are extracting the last character of the original string by specifying a negative start index of -1. This will return the character “!”.

Remember, the slice method in JavaScript provides a powerful way to extract substrings from strings based on index positions. Experiment with different start and end indices to extract the desired substring from your strings!