Hi everybody, can someone explain me ?

Question

let car=[13000, 23000, 100, 10];
let [price, tag, ...rest]=car;
let out=price+tag;
console.log(out/car.indexOf(...rest)); //outputs -36000

But I don't know how does car.indexOf(...rest) give me -1.
Need explaination please

Answer 1

You should know that general syntax of indexOf is,

Array.indexOf(elem, [startIdx])
So, car.indexOf(...rest) resolves to,
>>> [13000, 23000, 100, 10].indexOf(100, 10)

which means js finds 100 starting from 10th index, i.e., 11th element!

Now, you can think why result is -1
;-)

Answer 2

car.indexOf(rest[0])
Edit: you are searching an array with rest. car doesn't contain the array rest, it contains the values of that array. that's why it returns -1 because it didn't find a match.

Answer 3

Okay @vrintle & QTWizard thank y'all for your help. Now I see where was my mistake.
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