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in Technique[技术] by (71.8m points)

关于词法作用域的小疑惑;

词法作用域意味着作用域是由书写代码时函数声明的位置决定的。

那么

var value = 1; 
function foo() {
    console.log(value);
}

function bar() {
    var value = 2;
    foo();
}

bar(); // 1

这种情况是 1


function foo() {
    console.log(value);
}

function bar() {
    var value = 2;
    foo();
}


bar(); //undefined
var value = 1;

这种情况就输出为 undefined 啊
这个不是和函数调用位置无关么?


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1 Answer

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by (71.8m points)

是变量声明位置与函数调用位置无关,而不是赋值的位置无关哦


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