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Steven Gore
Steven Gore
Full Stack JavaScript Techdegree Student 9,279 Points

Please explain how [...planets] can be used?

I originally had the code like this and it worked. But I noticed in the final project, [...planet] was used. I don't understand how this works.

My original working code without [...planet]

const Container = (props) => { return ( <div class="container"> {props.planets.map((p) => ( <Planet url={p.url} name={p.name} desc={p.desc} moons={p.moons} diameter={p.diameter} key={p.id} /> ))} </div> ); };

1 Answer

Robert Bourton
Robert Bourton
6,179 Points

The Spread Operator There are many ways you can use the spread operator.

const numbers = [ 1, 2, 3 ]

function print( one, two, three) {

print( ...numbers )
function array( ...args ) {
   for (let i = 0; i < args.length; i++)
        console.log( args[i] )

array( 1, 2, 3)
const array1 = [ 1, 2, 3 ]
const array2 = [4, 5, 6 ]
const array3 = [ ...array1, ...array2 ]
let obj1 = { one: 1, two: 2 }
let obj2 = { three: 3, four: 4 }

let copy = { ...obj1 }
let merge = { ...obj1, ...obj2 }

I will need to see your whole code to help you out with this. Looks like your trying to build a HTML String.

Robert Bourton
Robert Bourton
6,179 Points

I don't use semicolons in my JavaScript code, since they are optional.

Steven Parker
Steven Parker
216,732 Points

Semicolons after statements may be technically optional, but they are most definitely a "best practice".
You might want to reconsider using them!   :speak_no_evil: