JavaScript Core Concept

1. Object

object is a collection of data that means object have name-value pairs. We can access data easily. You can add data also easily.

const object = {

name: ‘ebrahim’,

age : 22,

profession : ‘web development’

}

2. Array

Array is a similar of object is a collection of data. We can easly use it. Numeric data use only [] syntax. Array also have a property name is length . length declare easly how many data on this array.

const marks = [30,50,30,453,64]

const count = marks.length

console.log(count)

//Output = 5

3. pop()

pop() method remove a last element from any array. It’s a 0 based property used index 0. pop() method can change array length

const number = [54,42,73,75,53];

const removeElement = number.pop()

console.log(removeElement) //output 53

console.log(number) //ouput array[54,42,73,75,53]

4. push()

push() method can add on or more element included in a array. push() method also ) based property used index 0. Push method also change array length

const number = [54,42,73,75,53];

const addElement = number.push(23)

console.log(addElement) //output 23

console.log(number) //ouput array[54,42,73,75,53,23]

5. indexOf()

The position of an index of string is found through the indexOf() .

For example we declare any string than if you want to know index position you can use string prototype indexOf() like this:

const para = ‘my name is Rahim’

const str = ‘is’

const wordIndexOf = para.indexOf(‘str’)

6. toLowerCase()

This method converts any string current position to a lowercase position

const para=’JavaScript Is A Lightweight Programming Language’

console.log(para.toLowerCase());

//Output = javascript is a lightweight programming language

7.toUppercase()

This method convert any string current position to Uppercase position

const para = “javascript is a lightweight programming language”

console.log(para.toUpperCase())

8. Math.max()

This function returns the largest number from input parameters . also count maximum element of an array

console.log(Math.max(10, 30, 20));

// output: 30

9.Math.min()

This function returns the largest number from input parameters

console.log(Math.min(10, 30, 20));

// expected output: 10

10. forEach()

forEach() is a callback function this function execute once each element of an array

const word= [‘a’, ‘b’, ‘c’];

word.forEach(element => console.log(element));

// output: = “a”

// “b”

// “c”