🎉 init(first init project):

Author: 2495867729

README.md

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+<!--
+ * @Date: 2022-03-03
+ * @Description: 
+-->
+
+
+## type-chanllenges
+
+> [type-chanllenges](https://github.com/type-challenges/type-challenges)

easy/11-TupleToObject.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: Tuple to Object
+ */
+const tuple = ["tesla", "model 3", "model X", "model Y"] as const;
+
+type TupleToObject<T extends readonly any[]> = {
+    [K in T[number]]: K;
+};
+
+type result = TupleToObject<typeof tuple>; // expected { tesla: 'tesla', 'model 3': 'model 3', 'model X': 'model X', 'model Y': 'model Y'}
+
+export {};

easy/14-FirstOfArray.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description:First of Array
+ */
+type arr1 = ["a", "b", "c"];
+type arr2 = [3, 2, 1];
+
+type First<T extends any[]> = T extends [] ? never : T[0];
+
+type head1 = First<arr1>; // expected to be 'a'
+type head2 = First<arr2>; // expected to be 3\
+
+const test: head2 = 3;
+
+export {};

easy/18-LengthOfTuple.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: Length of Tuple
+ */
+type tesla = ["tesla", "model 3", "model X", "model Y"];
+type spaceX = [
+    "FALCON 9",
+    "FALCON HEAVY",
+    "DRAGON",
+    "STARSHIP",
+    "HUMAN SPACEFLIGHT"
+];
+
+type Length<K extends readonly any[]> = K["length"];
+
+type teslaLength = Length<tesla>; // expected 4
+type spaceXLength = Length<spaceX>; // expected 5
+
+export {};

easy/189-EasyAwaited.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: EasyAwaited
+ */
+
+type IUser = {
+    name: string;
+    age: number;
+};
+
+type PromiseType = Promise<IUser>;
+
+type EasyAwaited<T extends Promise<unknown>> = T extends Promise<infer R>
+    ? R extends Promise<unknown>
+        ? EasyAwaited<R>
+        : R
+    : never;
+
+type T1 = EasyAwaited<PromiseType>;

easy/268-If.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: If
+ */
+
+type If<T extends boolean, K, U> = T extends true ? K : U;
+
+type A = If<true, "a", "b">; // expected to be 'a'
+type B = If<false, "a", "b">; // expected to be 'b'
+
+export {};

easy/3057-Push.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: Push
+ */
+
+type Push<T extends readonly any[], U> = [...T, U];
+
+type Result = Push<[1, 2], "3">; // [1, 2, '3']
+
+export {};

easy/3060-Unshift.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: Unshift
+ */
+
+type Unshift<T extends unknown[], U> = [U, ...T];
+
+type Result = Unshift<[1, 2], 0>; // [0, 1, 2,]
+
+export {};

easy/3312-Parameters.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: Parameters
+ */
+
+type MyParameters<T> = T extends (...args: infer R) => any ? R : any;
+
+type F1 = (x: number) => string;
+
+type Result = MyParameters<F1>; // [x:number]
+
+export {};

easy/4-Pick.ts

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+/*
+ * @Date: 2022-03-03
+ * @Description: Pick
+ */
+interface Todo {
+    title: string;
+    description: string;
+    completed: boolean;
+}
+
+type MyPick<T, K extends keyof T> = {
+    [P in K]: T[K];
+};
+
+type TodoPreview = MyPick<Todo, "title" | "completed">;
+
+const todo: TodoPreview = {
+    title: "Clean room",
+    completed: false,
+};
+
+export {};