14 Most useful JavaScript String Methods

Abdullah Imran
3 min readNov 2, 2020

Strings are simply groups of characters, like ‘Hello’, ‘Good Morning!’. They are an important global object in JavaScript. They represent a sequence of characters. JavaScript has many powerful built-in functions that make working with strings easy for developers. Here I will explain some most important methods s of javascript strings.

  1. string.indexOf(substr, [start]) — returns the index position of character value passed with method. If not found, -1 is returned.

2. string.lastIndexOf(substr, [end]) — returns the last index position of character value passed with method. If not found, -1 is returned.

3. string.replace(originalstr,newstr) — search for a specified regular expression in a given string and then replace it if the match occurs.

4. string.slice(start, [end]) — returns a substring of the string based on the “start” and “end” index arguments.

5. string. split() — converts a string into an array. You have to pass a character such as a comma (,) or space to tell where to split the string.

6. string.trim() — returns a new string with removed white space from the start and end of the string.

7. string.trimStart() — returns a new string with removed white space from the start of the string.

8. string.trimEtart() — returns a new string with removed white space from the end of the string.

9. string.charAt(x) — Returns the character at the “x” position within the string.

10. string.concat(string1, string2, …) — Combines one or more strings into the existing one and returns the combined string.

Note: Original string is not modified.

11. string.includes(searchString) — returns whether searching String may be found in the source string.

12. string.toUpperCase() — Returns the string with all of its characters converted to uppercase.

This method doesn’t make any change in the original string.

13. string.toLowerCase() — Returns the string with all of its characters converted to lowercase.

This method doesn’t make any change in the original string.

14. string.ends With(searchString[, length]) — returns whether the source string ends with the searching string.

I hope this lesson provides a clear understands of how to string methods works in JavaScript. Hopefully, you learned something today. Happy Coding.

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