这个 JS 错是为什么？

V2EX = way to explore

V2EX 是一个关于分享和探索的地方

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var f = function() { console.log('I am outside!'); } (function s() { var f = function() { console.log('I am inside!'); } f(); }()); f();

"C:\Program Files\JetBrains\IntelliJ IDEA 2018.1.4\bin\runnerw.exe" C:\nodejs\node.exe C:\path\to\projects\test\src\test\test.js I am inside! C:\path\to\projects\test\src\test\test.js:8 f(); I am outside! ^

TypeError: f is not a function at Object.<anonymous> (C:\path\to\projects\test\src\test\test.js:8:1) at Module._compile (internal/modules/cjs/loader.js:689:30) at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10) at Module.load (internal/modules/cjs/loader.js:599:32) at tryModuleLoad (internal/modules/cjs/loader.js:538:12) at Function.Module._load (internal/modules/cjs/loader.js:530:3) at Function.Module.runMain (internal/modules/cjs/loader.js:742:12) at startup (internal/bootstrap/node.js:283:19) at bootstrapNodeJSCore (internal/bootstrap/node.js:743:3)</anonymous>

Process finished with exit code 1

13 条回复 2019-04-01 20:29:22 +08:00

ccccccc

2019-04-01 14:33:36 +08:00

注意分号

yuanfnadi

2019-04-01 14:35:35 +08:00

let f = function() {
console.log('I am outside!');
};
(function s() {
let f = function() {
console.log('I am inside!');
};
f();
})();

f();

请格式化代码。

azh7138m

2019-04-01 14:37:23 +08:00

https://prettier.io/playground/#N4Igxg9gdgLgprEAuEA3AhgJwAQDNsC8eArlGDAJbQAUAlNsNpFAM4QA2cAdOxAObUA5AEls6ALbYIxGCwoATOAEJBtANzYAvgB0o1XKXJUo2FnQa7sV7Bhz4iBspRr1GzNpx78hoidgqsCsqqGjom1rh0arqadOq6upHqIAA0IBAADs6syKBYmBAA7gAKWAgsyCDoqBAKqSAARpjoYADWcDAAyhktAXzIMJjEcGkAFjDi7ADqoxTwLD1gcJ3lcxSocwCelWAsFWkBLHCYMMXNfOLoyLjo7EdpAFYsAB4AQs1tHZ0ScAAyAXBrrd7iAns9On1OABFYgQeBAu4jEA9TBHTCVBroBqbXhQeoZTABGBTBQwUbIAAcAAY0gSIEcps0MpUCXA0ahAWlMHAAI7ECjcs7oC5XJA3RFpI7iCgDIZIuRQPjQ2HwsXApEwLEk+Rk5AAJjSg3QFHYfQAwhBxJdKlBoJyQMQjgAVLEVNWIzSaIA

请格式化代码+1

no1xsyzy

2019-04-01 14:37:32 +08:00

@ccccccc 可以，眼尖

azh7138m

2019-04-01 14:43:55 +08:00

@no1xsyzy 这不是眼尖吧，这是个 ASI 的问题了........

liujianwei

2019-04-01 14:48:54 +08:00

明白了！

```
var f = function() { console.log('I am outside!') }

;(function s() {
var f = function() { console.log('I am inside!') }
f()
}())

f()
```

对于不喜欢加分号的我，只要对行首字符进行判断，如果是 `[ ( + - / `五个符号之一，就在行首加分号。