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Abhishek Rath
Abhishek Rath

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Some popular string Methods in JavaScript

What is a String?

  • The sequence of one or more characters enclosed within quotation marks is called a string.
  • The quotation can be single quotes '' or double quotes " " or backtick ``.
  • And, the sequence of characters can be alphabets, numbers, symbols, etc.

Example of creating strings
Create string

Some commonly used JavaScript methods:

  1. Length
  • As the name suggests, length returns the length of the string.

  • Note, in the above example the whitespace, comma, and exclamation mark are also part of the string.


  • The charAt() returns the character at a specified index in a string.
  • The very first character of the string has an index of 0, the second character has index 1, and so on...


3.substring(start, end)

  • This method extracts the part of the string between start and end and returns the substring.


4.substr(start, length)

  • The substr() method returns the specified number of characters from the specified index (start parameter) from a given string.
  • Here, start defines the starting index from where the substring is to be extracted from the original string.
  • And, length defines the number of characters to be extracted from the specified start index.
  • Note: If the length parameter isn't given, then all the characters from start till the end of the string are extracted.



  • The concat() method joins two or more strings.
  • The concat() method doesn't modify the original strings, but it returns a new string. concat


  • The toUpperCase() method converts the strings to upper case letters. toUpperCase()


  • The toLowerCase() method converts the strings to lower case letters. lower case

8.slice(start, end)

  • The slice() method extracts and returns a part of the string from start to (excluding) the end character.
  • If there's no second argument specified, then the slice method extracts till the end of the string.


  • slice() also works on negative indices. If a negative index is specified, the string is extracted from the right end.
  • The negative index starts from -1 and it indicates the last character of the string, -2 is the second last character, and so on... slice


  • The replace() method is used to replace a part of a given string with a new substring.
  • One important thing to note here is that the replace() method does not change the original string on which it is called upon. It simply returns a new string.



  • The includes() method does a case-sensitive search on the original string to see if the specified substring is present in the string or not.
  • If the specified string is present, the method returns true otherwise false. includes


  • The trim() method removes leading and trailing whitespaces from the given string. trim


  • That is all from my side. I hope this article provides you with the basics of some popular string methods used in JavaScript.
  • Working through the examples is the best idea to understand these methods. Play with the examples.

Keep Learning!!

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