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Introduction to React

bookES6 Spread Operator

The spread operator (…) can be easily used to assign an array's values to another array.


              
123

            
let arr = [5, 6, 7, 8, 9];
let numbers = [1, 2, 3, 4, ...arr];
console.log (numbers);
copy

Changing the position of the...arr term will change the position of data in the output:


              
123

            
let arr = [5, 6, 7, 8, 9];
let numbers = [1, 2, ...arr, 3, 4];
console.log (numbers);
copy

The spread operator … unpacks the array arr elements and places them at the location. This can be used in many flexible ways, like passing arguments to a function:


              
12345

            
let values = [1, 7, 9];
function sum(a, b, c) {
    return a + b + c;
}
console.log (sum(...values));
copy

Task

Complete the following code by creating a new array called numbers and append the elements of both even and odd arrays (in this order) to the numbers array. Do it in a single line of code.

question-icon

Fill in the gaps.

const even = [2, 4, 6, 8];
const odd = [1, 3, 5, 9];
// Write code below this line
= [,]
// White code above this line
console.log (numbers.sort ());
[1, 2, 3, 4, 5, 6, 8, 9]

Click or drag`n`drop items and fill in the blanks

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 1. ChapterΒ 7

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bookES6 Spread Operator

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The spread operator (…) can be easily used to assign an array's values to another array.


              
123

            
let arr = [5, 6, 7, 8, 9];
let numbers = [1, 2, 3, 4, ...arr];
console.log (numbers);
copy

Changing the position of the...arr term will change the position of data in the output:


              
123

            
let arr = [5, 6, 7, 8, 9];
let numbers = [1, 2, ...arr, 3, 4];
console.log (numbers);
copy

The spread operator … unpacks the array arr elements and places them at the location. This can be used in many flexible ways, like passing arguments to a function:


              
12345

            
let values = [1, 7, 9];
function sum(a, b, c) {
    return a + b + c;
}
console.log (sum(...values));
copy

Task

Complete the following code by creating a new array called numbers and append the elements of both even and odd arrays (in this order) to the numbers array. Do it in a single line of code.

question-icon

Fill in the gaps.

const even = [2, 4, 6, 8];
const odd = [1, 3, 5, 9];
// Write code below this line
= [,]
// White code above this line
console.log (numbers.sort ());
[1, 2, 3, 4, 5, 6, 8, 9]

Click or drag`n`drop items and fill in the blanks

Everything was clear?

How can we improve it?

Thanks for your feedback!

SectionΒ 1. ChapterΒ 7
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