如何在JavaScript函数内访问相同变量名？

Question

如何在JavaScript函数内部访问相同的变量名？

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

- maheshv13

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在函数内部只使用 console.log("inside function: " + xyz + " World!") 而不给 xyz 分配任何值，这样怎么样？ - AKS

Answer 1

尝试：

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();

- Anupam Singh

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谢谢！ :) Anupam，回复得真快。我明白了。 - maheshv13

Answer 2

如果你不想编辑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();

如果你想编辑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();

- warch

---

谢谢！Christopher。 :) - maheshv13

Answer 3

尝试使用window。这将允许您访问全局声明的变量。 var xyz = window.xyz ..

- Sandeep Kokate

Answer 4

为什么不直接将其作为参数传递？完全没有必要使用global变量。

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);

- Sotiris Kiritsis