var arr1 = [{
id: 12,
name: 20
}, {
id: 13,
name: 30
}];
var arr2 = [{
id: 12,
title: 500
}, {
id: 13,
title: 666
}];
var sum = [];
for (var i = 0; i < arr1.length; i++) {
var obj = {
id: arr1[i].id,
name: arr1[i].name,
title: arr2[i].title
};
sum.push(obj);
}
console.log(sum);