Bitwise &

[Valbou]

Hi,

Can you explain this JS behavior ?

const maxi = 63
console.log(`Safe integer until ${Number.MAX_SAFE_INTEGER}`)

for (let i=0; i < maxi; i++) {
    const powValue = Math.pow(2, i)
    const result = powValue & powValue

    console.log(`${i} -> ${powValue} -> ${result}`)
}

Why I get negative value when i == 31 and 0 after. It seems to match integer standard size (integer overflow).
Some other languages have consistent values over 32 bits. At least on x64 CPU.

Values seem approximate after i > 53 (according to Number.MAX_SAFE_INTEGER safe limit)

Thanks !