数组之间的加减

var comp = [120, 132, 101, 134, 90, 230, 210];
var comp2=[220, 182, 191, 234, 290, 330, 310];

var arr=[];

for(var i=0;i<comp.length;i++){
    arr.push(comp2[i]-comp[i])
}
console.log(arr);