函數的參數傳遞:
1.傳遞基本類型值:
function addTen(num) {
num = num + 10;
return num;
}
var count = 20;
var result = addTen(count);
alert(count); //20
alert(result); //30
2.傳遞引用類型值:
function setName (obj) {
obj.name = "Nicolas";
}
var person = new Object();
setName(person);
alert(person.name); //"Nicolas" 看起來像按引用傳遞,但是↓
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function setName (obj) {
obj.name = "Nicolas";
obj =new Object();
obj.name = "Greg";
}
var person = new Object();
setName(person);
alert(person.name); //如果是按引用傳遞,這裏應該輸出是“Greg”,但是輸出結果是“Nicolas”
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