Mostly used Array methods

Map: it is used to transform the data and return new array without affecting the existing one.

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

let newArray = array.map((val) => {

return val * 10;

});

console.log(‘Original Array = ‘, array); // [1, 2, 3, 4, 5]

console.log(‘Modified Array = ‘, newArray); // [10, 20, 30, 40, 50]

Filter: It can be used to create new array with elements passes the condition given by function or user.

let array = [1,2,3,4,5,6,7];

let newArray = array.filter((val) => {

return val % 2 === 0;

});

console.log(‘Original Array = ‘, array); // [1, 2, 3, 4, 5, 6, 7]

console.log(‘Modified Array = ‘, newArray); // [2, 4, 6]

Reduce: It is returning one value which is accumulated result of the function. It doesn’t affect the original array but create new one.

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

let result = array.reduce((total, currentValue) => {

return total + currentValue;

});

console.log(‘Result = ‘, result); // Result = 15

indexOf: This method returns the first index of specified value else returns -1.

In order to check particular element exist in an array or not we can use indexOf, includes methods as well.

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

let index = array.indexOf(4);

console.log(‘Index = ‘, index); // Index = 3

Push: It is used to push new element in an array.

let array = [1,2,3,4];

array.push(5);

console.log(‘Array = ‘, array); // Array = [1, 2, 3, 4, 5]

Pop: It is used to remove the last index value from array.

let array = [1,2,3,4];

array.pop();

console.log(‘Array = ‘, array); // Array = [1, 2, 3]

forEach: This function calls method for each element of an array. It doesn’t return any value or return undefined.

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

let sum = 0;

array.forEach((val) => {

sum = sum + val;

});

console.log(‘Sum = ‘, sum);

Reverse: This method is used to reverses the array and overwrites the original array.

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

array.reverse();

console.log(‘Reversed Array = ‘, array); // Reversed Array = [5, 4, 3, 2, 1]

to be continued…