基础类型

string

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let str:string = 'hello'
let str2:string = `${str} world`
console.log(str2)

输出hello world

number

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8
9
10
11
12
let num:number = 114514
let num2:number = NaN
let num3:number = Infinity
let num4:number = 0o11
let num5:number = 0x11
let num6:number = 0b11
console.log(num)
console.log(num2)
console.log(num3)
console.log(num4)
console.log(num5)
console.log(num6)

输出

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5
6
114514
NaN
Infinity
9
17
3

boolean

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let flag:boolean = true
let flag2:boolean = Boolean(0)
console.log(flag)
console.log(flag2)

输出

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true
false

void

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let u:void = undefined
// @ts-ignore
let n:void = null
console.log(u)
console.log(n)

输出

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undefined
null

null、undefined

可以交叉使用，不过通常不这样做

与void相比，可以为基础类型变量赋值，而void不可以