Clear bit
JavaScript
var ori = 117 // original value
var ori_mask = 117 & 0xF4; // clear bit 1 and 2
console.log('original : ' + ori.toString(2))
console.log('Clear first two bits : ' + ori_mask.toString(2))
var replace =10; //
ori_mask |= replace;
console.log('Result : ' + ori_mask.toString(2))