//// [typeGuardOfFormInstanceOfOnInterface.ts] // A type guard of the form x instanceof C, where C is of a subtype of the global type 'Function' // and C has a property named 'prototype' // - when true, narrows the type of x to the type of the 'prototype' property in C provided // it is a subtype of the type of x, or // - when false, has no effect on the type of x. interface C1 { (): C1; prototype: C1; p1: string; } interface C2 { (): C2; prototype: C2; p2: number; } interface D1 extends C1 { prototype: D1; p3: number; } var str: string; var num: number; var strOrNum: string | number; var c1: C1; var c2: C2; var d1: D1; var c1Orc2: C1 | C2; str = c1Orc2 instanceof c1 && c1Orc2.p1; // C1 num = c1Orc2 instanceof c2 && c1Orc2.p2; // C2 str = c1Orc2 instanceof d1 && c1Orc2.p1; // C1 num = c1Orc2 instanceof d1 && c1Orc2.p3; // D1 var c2Ord1: C2 | D1; num = c2Ord1 instanceof c2 && c2Ord1.p2; // C2 num = c2Ord1 instanceof d1 && c2Ord1.p3; // D1 str = c2Ord1 instanceof d1 && c2Ord1.p1; // D1 var r2: D1 | C2 = c2Ord1 instanceof c1 && c2Ord1; // C2 | D1 //// [typeGuardOfFormInstanceOfOnInterface.js] // A type guard of the form x instanceof C, where C is of a subtype of the global type 'Function' // and C has a property named 'prototype' // - when true, narrows the type of x to the type of the 'prototype' property in C provided // it is a subtype of the type of x, or // - when false, has no effect on the type of x. var str; var num; var strOrNum; var c1; var c2; var d1; var c1Orc2; str = c1Orc2 instanceof c1 && c1Orc2.p1; // C1 num = c1Orc2 instanceof c2 && c1Orc2.p2; // C2 str = c1Orc2 instanceof d1 && c1Orc2.p1; // C1 num = c1Orc2 instanceof d1 && c1Orc2.p3; // D1 var c2Ord1; num = c2Ord1 instanceof c2 && c2Ord1.p2; // C2 num = c2Ord1 instanceof d1 && c2Ord1.p3; // D1 str = c2Ord1 instanceof d1 && c2Ord1.p1; // D1 var r2 = c2Ord1 instanceof c1 && c2Ord1; // C2 | D1