10 JavaScript Array Methods

   10 JavaScript Array Methods to Know:

1. forEach()
This method can help you to loop over array's items.
 

    var ar_1 = [1, 2, 3, 4, 5, 6];

 ar_1.forEach(item => {
     console.log(item); // Output: 1 2 3 4 5 6
 });

2. includes()
This method check if array includes the item passed in the method.
 

    var ar_2 = [1, 2, 3, 4, 5, 6];

 console.log(ar_2.includes(2)); //true
 console.log(ar_2.includes(7)); //false

3. filter()
This method create new array with only elements passed condition inside the provided function.
 

    var ar_3 = [1, 2, 3, 4, 5, 6];

 // item(s) greater than 3
 var filtered = ar_3.filter(num => num > 3);
 console.log(filtered); // Output: [4, 5, 6]

 console.log(ar_3); // Output: [1; 2, 3, 4, 5, 6]

4. map()
This method create new array by calling the provided function in every element.
 

    var ar_4 = [1, 2, 3, 4, 5, 6];

 // add one to every element
 var oneAdded = ar_4.map(num => num +1);
 console.log(oneAdded); // Output: [2, 3, 4, 5, 6, 7]
 
 console.log(ar_4); // Output: [1; 2, 3, 4, 5, 6]

5. reduce()
The reduce() method applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value
 

    var ar_5 = [1, 2, 3, 4, 5, 6];

 var sum = ar_5.reduce((total, value) => total + value, 0);

 console.log(sum); // 21

 
6. some()
This method checks if at least one of array's item passed the condition. If passed, it return 'true' otherwise 'false'.

    var ar_6 = [1, 2, 3, 4, 5, 6];

 // at least one element is greater than 4?
 const largeNum = ar_6.some(num => num > 4);
 console.log(largeNum); // Output: true


 // at least one element is less than or equal to 0?
 const smallNum = ar_6.some(num => num <= 0);
 console.log(smallNum); // Output: false

 
7. every()
This method checks if all array's item passed the condition. If passed, it return 'true' otherwise 'false'.

    // all elements are greater than 4
 var greaterFour = ar_7.every(num => num > 4);
 console.log(greaterFour); // Output: false


 // all elements are less than 10
 var lessTen = ar_7.every(num => num < 10);
 console.log(lessTen); // Output: true

8. sort()
This method is used to arrange/sort array's item either ascending or descending order.
 

    var ar_8 = [1, 2, 3, 4, 5, 6];
 var alpha = ['e', 'a', 'c', 'u', 'y'];


 // sort in descending order
 descOrder = ar_8.sort((a, b) => a > b ? -1 : 1);
 console.log(descOrder); // Output: [6, 5, 4, 3, 2, 1]


 // sort in ascending order
 ascOrder = alpha.sort((a, b) => a > b ? 1 : -1);
 console.log(ascOrder); // Output: ['a', 'c', 'e', 'u', 'y']

 
9. Array.from()
This changes all things that are array-like or iterable into a true array especially when working with DOM, so that you can use other array methods like reduce, map, filter and so on.

    var name = 'SoloLearn';
 var nameArray = Array.from(name);

 console.log(name); // Output: 'SoloLearn'
 console.log(nameArray); // Output: ['S', 'o', 'l', 'o', 'L', 'e', 'a', 'r', 'n']

10. Array.of()
This create array from every arguments passed into it.
 

    var nums = Array.of(1, 2, 3, 4, 5, 6);
 console.log(nums); // Output: [1, 2, 3, 4, 5, 6]


    HappyLearning!:) by_@boolean_maybe