非嚴格模式下

var oMyself = {
    sFirstname: "Aidan",
    sLastName: "Dai"
}

function create(){
    var sLastName = "Wen"
    with(oMyself){
        //將oMyself作為自己的執行環境
        sAllName = sFirstname +" " + sLastName;
    }
    return sAllName;
}
var sMyName = create();
console.log(sMyName); //Aidan Dai

var
 
 oMyself = {
    sFirstname: "Aidan",
}

function create(){
    var sLastName = "Wen"
    with(oMyself){
        //將oMyself作為自己的執行環境
        sAllName = sFirstname +" " + sLastName;
    }
    return sAllName;
}
var sMyName = create();
console.log(sMyName); //Aidan Wen

注：嚴格模式下會報錯
當使用with語句時，相當於在現在的作用域頂部上添加了傳遞給with的物件