JSFiddle - React, Tailwind, and code Playground

JavaScript

//bounds of correctness ~~(x) и 0|x
//as replacement of Math.floor(x)

above=Number.MAX_SAFE_INTEGER
below=0

eps_prev = undefined
eps=above-below
while(!eps_prev || eps<eps_prev){
  middle=above/2+below/2
  if(~~(middle) == Math.floor(middle)) below = middle
  else above = middle
  eps_prev = eps
  eps = above-below
}

above == 2147483648 //Math.pow(2, 31)
below == 2147483647.9999998

~~(2147483648) != Math.floor(2147483648)
~~(2147483647.9999998) == Math.floor(2147483647.9999998)

~~(2147483648-1e-7) != Math.floor(2147483648-1e-7)
~~(2147483648-1e-6) == Math.floor(2147483647-1e-6)

~~(0) == Math.floor(0)
~~(-Number.EPSILON) != Math.floor(-Number.EPSILON)

//0<=x<=2147483647.9999998