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Title: Parameter Defaults See Scope of Function Body · Issue #8465 · microsoft/TypeScript · GitHub

Open Graph Title: Parameter Defaults See Scope of Function Body · Issue #8465 · microsoft/TypeScript

X Title: Parameter Defaults See Scope of Function Body · Issue #8465 · microsoft/TypeScript

Description: TypeScript Version: 1.8.10 Code namespace A { "use strict"; let foo = "out"; export function bar(func = () => foo) { let foo = "in"; console.log(func()); } } A.bar(); Expected behavior: I read http://www.2ality.com/2015/02/es6-scoping.ht...

Open Graph Description: TypeScript Version: 1.8.10 Code namespace A { "use strict"; let foo = "out"; export function bar(func = () => foo) { let foo = "in"; console.log(func()); } } A.bar(); Expected behavior: I read http...

X Description: TypeScript Version: 1.8.10 Code namespace A { "use strict"; let foo = "out"; export function bar(func = () => foo) { let foo = "in"; console.log(func()); } } A.bar(...

Opengraph URL: https://github.com/microsoft/TypeScript/issues/8465

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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Parameter Defaults See Scope of Function Body","articleBody":"**TypeScript Version:** \n\n1.8.10\n\n**Code**\n\n``` ts\nnamespace A {\n    \"use strict\";\n    let foo = \"out\";\n    export function bar(func = () => foo) {\n        let foo = \"in\";\n        console.log(func());\n    }\n}\nA.bar();\n```\n\n**Expected behavior:**\nI read http://www.2ality.com/2015/02/es6-scoping.html (section: _5.3. Parameter default values don’t see the scope of the body_) and then tried out:\n\n``` js\n(() => { \"use strict\"; let v = \"out\"; ((f = () => v) => { let v = \"in\"; console.log(f())})()})()\n```\n\nin node v6.0.0 and got the value `'out'`.\n\n**Actual behavior:** \nWhat TypeScript generates gives you the result `'in'`.\n\nDoesn't matter if you swap `var` for `let`.\n","author":{"url":"https://github.com/SlurpTheo","@type":"Person","name":"SlurpTheo"},"datePublished":"2016-05-04T19:01:22Z","url":"https://github.com/microsoft/TypeScript/issues/8465"}

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