var man = 'Tony';
function family1(){
family2();
console.log('你好' + man);//Tony
function family2(){
var man = 'John';
console.log('你好' + man);//John
}
}
family1();
一開始執行family1函式、再執行family2,當family2裡面需告一個man變數,其值為John且輸出結果會是John,但是family1本身沒有宣告任何man變數,所以結果會是去尋找外層的Tony
參考文獻:
← Home 提升(Hoisting) →