Create a boolean array " prime [ 0 . . n ] " and initialize all entries it as true . A value in prime [ i ] will finally be false if i is Not a prime , else true .
let prime = new Array ( MAX ) ; for ( let i = 0 ; i < prime . length ; i ++ ) { prime [ i ] = true ; } for ( let p = 2 ; p * p < MAX ; p ++ ) {