TypeScript
interface Shape {
color: string;
}
interface Square extends Shape {
sideLength: number;
}
let square = {};
square.color = "blue";
square.sideLength = 10;
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对应生成的JavaScript：
var square = {};
square.color = "blue";
square.sideLength = 10;
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TypeScript
interface Shape {
color: string;
}
interface PenStroke {
penWidth: number;
}
interface Square extends Shape, PenStroke {
sideLength: number;
}
let square = {};
square.color = "blue";
square.sideLength = 10;
square.penWidth = 5.0;
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对应的JavaScript代码：
var square = {};
square.color = "blue";
square.sideLength = 10;
square.penWidth = 5.0;
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extends ___ = ___ syntax in typescript
export interface ActionReducer {
(state: T | undefined, action: V): T;
}
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It specifies the default type of V . so V can be either a class which extends Action or if not mentioned will be of type Action.
