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在 chrome 开发工具上执行 javascript 代码时出现问题

[英]Issue executing javascript code on chrome dev-tools

I tried to execute this code:我试图执行这段代码:

html code: html 代码:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="variables.js"></script>
</head>
<body>
    
</body>
</html>

js code: js代码:

const var1 = 10;
const var2 = 'Hello world';
const var3 = true;

const foo = function(){
    console.log("Whats up !!");
}();

foo;

console.log(typeof(foo));

When I am opening this javascript file and executing this javascript over browser chrome devtools inspector, its neither letting me create the founction foo(), nor is it letting me use foo().当我打开这个 javascript 文件并通过浏览器 chrome devtools 检查器执行这个 javascript 时,它既不让我创建函数 foo(),也不让我使用 foo()。

I am not able to figure out the reason for it.我无法弄清楚它的原因。 Help is appreciated.感谢帮助。

Tried to execute js in chrome dev tools.试图在 chrome 开发工具中执行 js。

Did not worked for me.没有为我工作。

Error code:错误代码:

enter image description here在此处输入图像描述

When you created a 'foo' function you called it.当你创建一个 'foo' function 时,你调用了它。 So your function is IIFE(Immediately Invoked Function Expression), that's why your 'foo' is undefined, because your IIFE called and returned undefined.所以你的 function 是 IIFE(立即调用 Function 表达式),这就是你的 'foo' 未定义的原因,因为你的 IIFE 调用并返回未定义。

just don't call the function when you assign it to a variable.只是在将其分配给变量时不要调用 function。

const var1 = 10;
const var2 = 'Hello world';
const var3 = true;

const foo = function(){
    console.log("Whats up !!");
};

foo();

console.log(typeof(foo));

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