Strings cheatsheet in Javascript

If you want to become a good Developer then you must need to have a good command over the basics of the language you're dealing with. When it comes to Javascript, Strings are one of the strong pillars. Now we are going see some of the methods that you can apply on strings.

String cheatsheet

For this post we are going to use this example

const sentence = 'Hello onecompiler'

So lets get started!

1. length

// sentence.length => returns the length of string
console.log(sentence.length) // output: 17

2. indexOf()

// sentence.indexOf('Hello') => returns the staring index of first occurence, if not found returns -1
console.log(sentence.indexOf('Hello')) // output: 0

3. lastIndexOf()

// sentence.indexOf('Hello') => returns the staring index of last occurence, if not found returns -1
console.log(sentence.lastIndexOf('Hello')) // output: 0

4. replace()

// sentence.replace('Hello', 'Hey') => replaces the first string with second
console.log(sentence.replace('Hello', 'Hey')) // output: Hey onecompiler

5. substr()

// sentence.substr(1,2) => returns substring starting from index 5 of length 2
console.log(sentence.substr(1,2)) // output: el
// if we ignore length param
console.log(sentence.substr(1)) // output: ello onecompiler 

6. includes()

// sentence.includes('Hello') => checks if a string exists in given string (case-sensitive)
console.log(sentence.includes('Hello')) // output: true

7. endsWith()

// sentence.endsWith('Hello') => checks if a string ends with given string (case-sensitive)
console.log(sentence.endsWith('Hello')) // output: false

8. startsWith()

// sentence.startsWith('Hello') => checks if a string starts with given string (case-sensitive)
console.log(sentence.startsWith('Hello')) // output: true

9. charAt()

// sentence.charAt(1) => character at index 1
console.log(sentence.charAt(1)) // output: 'e'

10. toUpperCase()

// sentence.toUpperCase() => convert string into uppercase
console.log(sentence.toUpperCase()) // output: HELLO ONECOMPILER

11. toLowerCase()

// sentence.toLowerCase() => convert string into lowercase
console.log(sentence.toLowerCase()) // output: hello onecompiler

12. trim()

// sentence.trim() => removes spaces at start and end
console.log(sentence.trim()) // output: hello onecompiler

13. slice()

// sentence.slice(0,4) => returns a substring from specified indexes
console.log(sentence.slice(0,4)) // output: hello

14. split()

// sentence.split() => splits into strings seperated by spaces
console.log(sentence.slice(0,4)) // output: ['hello', 'onecompiler']

That's it guys, cheers!