var a = [1،2،4،32،128] ؛ var b = [] ؛ لـ (var i = 0 ؛ i <a.length ؛ i ++) {var index = math.log (a [i])/math.log (2) ؛ b.push (index) ؛} // b = [0،1،2،5،7] ؛