extend简单用法

eg:
var obj1=[{a:1,b:2},{a:2,b:3}]

var obj2=[{c:3,d:2},{c:4,d:3}]

var resultArray=[];
for (var i = 0; i < obj1.length; i++) {
for (var j = 0; j < obj2.length; j++) {
if (obj1[i].b == obj2[j].d) {
resultArray=($.extend(obj1[i], obj2[j]));
}
}
}

结果：resultArray=[{a:1,b:2，c:3,d:2},{a:2,b:3,c:4,d:3}]