32 lines
1.9 KiB
TypeScript
32 lines
1.9 KiB
TypeScript
//// [arrayLiteralExpressionContextualTyping.ts]
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// In a contextually typed array literal expression containing no spread elements, an element expression at index N is contextually typed by
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// the type of the property with the numeric name N in the contextual type, if any, or otherwise
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// the numeric index type of the contextual type, if any.
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var array = [1, 2, 3];
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var array1 = [true, 2, 3]; // Contextual type by the numeric index type of the contextual type
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var tup: [number, number, number] = [1, 2, 3, 4];
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var tup1: [number|string, number|string, number|string] = [1, 2, 3, "string"];
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var tup2: [number, number, number] = [1, 2, 3, "string"]; // Error
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// In a contextually typed array literal expression containing one or more spread elements,
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// an element expression at index N is contextually typed by the numeric index type of the contextual type, if any.
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var spr = [1, 2, 3, ...array];
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var spr1 = [1, 2, 3, ...tup];
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var spr2:[number, number, number] = [1, 2, 3, ...tup]; // Error
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//// [arrayLiteralExpressionContextualTyping.js]
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// In a contextually typed array literal expression containing no spread elements, an element expression at index N is contextually typed by
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// the type of the property with the numeric name N in the contextual type, if any, or otherwise
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// the numeric index type of the contextual type, if any.
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var array = [1, 2, 3];
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var array1 = [true, 2, 3]; // Contextual type by the numeric index type of the contextual type
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var tup = [1, 2, 3, 4];
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var tup1 = [1, 2, 3, "string"];
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var tup2 = [1, 2, 3, "string"]; // Error
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// In a contextually typed array literal expression containing one or more spread elements,
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// an element expression at index N is contextually typed by the numeric index type of the contextual type, if any.
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var spr = [1, 2, 3].concat(array);
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var spr1 = [1, 2, 3].concat(tup);
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var spr2 = [1, 2, 3].concat(tup); // Error
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