# Only half of array gets raised to power

I wanted to create binary to decimal calculator. When i tried to console log both of arrays (binary is array of 0’s and 1’s, binarypos is array of numbers that are powers of 2.

Screenshot

Then i created simpler version, made in console so chance of making a mistake lowered to zero. But the bug appears again!

```const x = Array(8).fill(1);

const xpos = Array(8).fill(0);

for (let i = 0; i < x.length; i++) {
xpos[x.length - 1 - i] = Number(x[i]);
xpos[i] = Math.pow(xpos[i] * 2, [i]);
}
console.log(xpos) // [1, 1, 1, 1, 16, 32, 64, 128]
```

I want it to look like this

```console.log(xpos) // [1, 2, 4, 8, 16, 32, 64, 128]
```

Wouldn’t it be simpler to just do something like this?

```const x = Array(8).fill(1);
const xpos = [];

for (let i = 0, j=1; i < x.length ; i++, j*=2 ) {
xpos[i] = j;
}
```

Or for what your screenshot suggests that you’re trying to accomplish: converting a string of binary digits (`0` or `1`) into its decimal representation, just:

```function binaryToDecimal( digits ) {
const isValid = /^[01]+\$/.test(digits);
if (!isValid) {
throw new TypeError("bindDigits must be a string containing only '0' and '1'.");
}

let value = 0;
let p = 1;
for ( const d of digits.split('').map( d => +d ).reverse() ) {
value += d * p;
p *= 2;
}

return value;
}
```
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