javascript中各种风骚的代码

1.判断数值符号是否相同

	function numericSymbolsIsEqual(x: number, y: number): boolean {return (x ^ y) >= 0}console.log(numericSymbolsIsEqual(1, 1))console.log(numericSymbolsIsEqual(-1, 1))console.log(numericSymbolsIsEqual(1, -1))console.log(numericSymbolsIsEqual(-1, -1))

输出如下

判断一个数n是否为2的整数幂

代码部分

	function isPowerOfTwo(n: number): boolean {return (n & (n - 1)) === 0}console.log(isPowerOfTwo(4))console.log(isPowerOfTwo(5))console.log(isPowerOfTwo(6))console.log(isPowerOfTwo(1024))console.log(isPowerOfTwo(1021))

输出如下

星级评分

enum Score {veryPoor = 1,poor,ordinary,good,veryGood
}
function starRating(n: Score): string {return '★★★★★☆☆☆☆☆'.slice(5 - n, 10 - n)
}
console.log(starRating(Score.veryPoor))
console.log(starRating(Score.poor))
console.log(starRating(Score.ordinary))
console.log(starRating(Score.good))
console.log(starRating(Score.veryGood))

输出如下

0和1切换

	function toggle(n: number): number {return n ^= 1}console.log(toggle(1))console.log(toggle(1))console.log(toggle(0))console.log(toggle(0))console.log(toggle(1))

浮点数向下取整

	function roundDownDoubleNon(n: number): number {return ~~n}function roundDownRightShift(n: number): number {return n >> 0}function roundDownLeftShift(n: number): number {return n << 0}function roundDownOr(n: number): number {return n | 0}console.log(roundDownDoubleNon(Math.PI))console.log(roundDownRightShift(Math.PI))console.log(roundDownLeftShift(Math.PI))console.log(roundDownOr(Math.PI))

x乘2的y次幂

	function getTwoYPower(x: number, y: number): number {return x << y}// 输出1乘2的2次方console.log(getTwoYPower(1, 2))// 输出2乘2的3次方console.log(getTwoYPower(2, 3))// 输出3乘2的2次方console.log(getTwoYPower(3, 2))

让天底下的代码再也没有bug

	try {//code} catch (error) {location.href = `https://baidu.com/esarch?q=js+${error.message}`}

这个就不做演示啦哈