Methods which we can use with array in JavaScript.

Methods which we can use with an array in JavaScript:-

Array : It is a collection of similar items in big brackets. Here Jobs is an array. It has different types of jobs name as string.

var Jobs = ['Doctor', 'Engineer', 'Lawyer', 'Carpenter', 'Technician', 'Clerk', 'Manager','Electrician','CA','Labour'];

includes(): This method checks in an array that a particular item it contains or not and if contain then return true else false. It is not supported by the Internet Explorer.

var item = Jobs.includes('Postman');
console.log(item);

//Output:
false

var item = Jobs.includes('CA');
console.log(item);

//Output:
true

indexOf(): This method determine in an array that a particular item it contains or not and if contains then return it first index else -1. It is supported all browser.

var item = Jobs.indexOf('Postman');
console.log(item);

//Output:
-1

var item = Jobs.indexOf('Lawyer');
console.log(item);

//Output:
2


Array.forEach() : - This method calls a callback function and operate through each item of an array.

Jobs.forEach(function(d){
//It will give each item of array one by one till last item.
console.log(d);
});

or ES6

Jobs.forEach(d=> {
////It will give each item of array one by one till last item.
    console.log(d);
})
//Output:

Doctor
Engineer
Lawyer
Carpenter
Technician
Clerk
Manager
Electrician
CA
Labour

reduce() : - It will reduce an array to a single item;

let numbers = [ 2, 3, 1, 5, 4, 3 ];

// Get the sum of all numerical values
let sum = numbers.reduce((a, b) => {
    return a + b;
});

console.log(sum); 
//Output:
18

map(): It is a callback function which creates a new array with results of calling a function for every array elements.

var numArr= [65, 44, 12, 4];
var newNumArr= numArr.map(calculate) /callback function will add 10 in every item of array

function calculate(num) {
  return num + 10;
}

console.log(newNumArr);

//Output:
[75, 54, 22, 14]