ary-ptrn-elem-id-init-undef.js (1259B)
1 // This file was procedurally generated from the following sources: 2 // - src/dstr-binding/ary-ptrn-elem-id-init-undef.case 3 // - src/dstr-binding/default/let-stmt.template 4 /*--- 5 description: Destructuring initializer with an undefined value (`let` statement) 6 esid: sec-let-and-const-declarations-runtime-semantics-evaluation 7 features: [destructuring-binding] 8 flags: [generated] 9 info: | 10 LexicalBinding : BindingPattern Initializer 11 12 1. Let rhs be the result of evaluating Initializer. 13 2. Let value be GetValue(rhs). 14 3. ReturnIfAbrupt(value). 15 4. Let env be the running execution context's LexicalEnvironment. 16 5. Return the result of performing BindingInitialization for BindingPattern 17 using value and env as the arguments. 18 19 13.3.3.6 Runtime Semantics: IteratorBindingInitialization 20 21 SingleNameBinding : BindingIdentifier Initializeropt 22 23 [...] 24 6. If Initializer is present and v is undefined, then 25 a. Let defaultValue be the result of evaluating Initializer. 26 b. Let v be GetValue(defaultValue). 27 [...] 28 7. If environment is undefined, return PutValue(lhs, v). 29 8. Return InitializeReferencedBinding(lhs, v). 30 ---*/ 31 32 let [x = 23] = [undefined]; 33 34 assert.sameValue(x, 23); 35 36 reportCompare(0, 0);