如何在javascript中訪問函數內的相同變量名

Question

如何在javascript中訪問函數內的相同變量名

var xyz = "Hello";
console.log("outside function: " + xyz)
function abc() {
    var xyz = "World!";
    console.log("inside function: " + xyz) // output should be "Hello world!"
} abc();

Answer 1

試試：

var xyz = "Hello";
console.log("outside function: " + xyz)
function abc() {
    var xyz = (window.xyz || "") +" " + "World!";
    console.log("inside function: " + xyz) // output should be "Hello world!"
} abc();

Answer 2

如果您不想編輯xyz的值：

var xyz = "Hello";
console.log("outside function: " + xyz)
function abc() {
    var abc = " World!";
    console.log("inside function: " + xyz + abc) // output should be "Hello world!"
} abc();

如果你想編輯xyz的值：

var xyz = "Hello";
console.log("outside function: " + xyz)
function abc() {
    xyz += " World!";
    console.log("inside function: " + xyz) // output should be "Hello world!"
} abc();

Answer 3

試試窗口。 這將允許您訪問全局聲明的變量。

var xyz = window.xyz ..

Answer 4

為什么不把它作為參數傳遞？ 絕對不需要使用全局變量。

var xyz = "Hello";
console.log("outside function: " + xyz)
function abc(xyz) {
    var xyzUpdated = xyz + "World!";
    console.log("inside function: " + xyzUpdated) // output should be "Hello world!"
} abc(xyz);