Typescript数值扩展使用

//二,八,十六进制声明
let b = 0b11110000;
let o = 0o777;
let x = 0xffff;
console.log(b,o,x);
//进制转换
console.log(Number(0b11111111),Number(0xffffffff),Number(0o77777777));
//数值有限判断,除了数值,其它全部返回false
console.log(Number.isFinite(1.5));
console.log(Number.isFinite(0.4));
console.log(Number.isFinite(NaN));
console.log(Number.isFinite(undefined));
console.log(Number.isFinite(Infinity));//正无穷大
console.log(Number.isFinite(-Infinity));//负无穷大
console.log(Number.isFinite('hello'));
console.log(Number.isFinite('98'));
console.log(Number.isFinite(false));
//数值NaN判断
console.log(Number.isNaN(NaN));
console.log(Number.isNaN(80));
console.log(Number.isNaN('97'));
console.log(Number.isNaN(true));
console.log(Number.isNaN(999/NaN));
console.log(Number.isNaN('false'/0));
console.log(Number.isNaN('hello'/8));
console.log(Number.isNaN('OK'/'NO'));
//数值转换
console.log(Number.parseInt('89.65'))
console.log(Number.parseFloat('35.79@'));
console.log(Number.isInteger(98));
console.log(Number.isInteger(86.0));
console.log(Number.isInteger(98));
console.log(Number.isInteger('8888'));
console.log(Number.isInteger(false));
//最小常量,用于误差计算
console.log('可接受的误差范围:',Number.EPSILON);
//安全整数
console.log('js的最小与最大整数范围:',Math.pow(-2,53),Math.pow(2,53));
console.log(Math.pow(2,53) === (Math.pow(2,53) + 1))//true 计算结果不正确,后者比前者大1 ,因为超出2的53次方,计算不正确
console.log(Number.MIN_SAFE_INTEGER,Number.MAX_SAFE_INTEGER);
console.log(Number.isSafeInteger(Number.MAX_SAFE_INTEGER));
console.log(Number.isSafeInteger(Number.MIN_SAFE_INTEGER));
console.log(Number.isSafeInteger(Number.MAX_SAFE_INTEGER+1));//false 非安全整数范围内
console.log(Number.isSafeInteger(Number.MIN_SAFE_INTEGER-1));//false 非安全整数范围内
//取浮点数整数部分
console.log(Math.trunc(8.9),Math.trunc(-9.78),Math.trunc(-0.59),Math.trunc(0.9999));
console.log(Math.trunc(NaN),Math.trunc('hello'),Math.trunc());//不传参数或者非数值都返回NaN
//正负值判断
console.log(Math.sign(9),Math.sign(-3),Math.sign(0),Math.sign(-0));//0返回正负0,其它正数返回1,负数返回-1
//求立方根
console.log(Math.cbrt(27),Math.cbrt(8),Math.cbrt(-27),Math.cbrt(0),Math.cbrt(1),Math.cbrt('hello'));//非数值返回NaN
//求一个整数的二进制形式的32位无符号整数形式的前导0的个数
console.log(Math.clz32(0));
let zero=0;
let clz32Count = Math.clz32(zero);
console.log('0的二进制是:',`0b${'0'.repeat(32)}`);
//浮点数,只计算整数部分
console.log(Math.clz32(1.111))//31
//数值外的其它类型全部返回32个前导0
console.log(Math.clz32(true));
console.log(Math.clz32());
console.log(Math.clz32(NaN));
console.log(Math.clz32(undefined));
console.log(Math.clz32(null));
console.log(Math.clz32('ok'));
console.log(Math.clz32([]));
console.log(Math.clz32({}));
//求积
console.log(Math.imul(2,8),Math.imul(-2,-8),Math.imul(-4,16));
console.log(0x7fffffff,Math.imul(0x7fffffff,0x7fffffff));//Math.imul在计算超出2的53次方的数值时,可正确返回低位
//求数值的浮点表示形式
console.log(Math.fround(3.1415),Math.fround(1.20),Math.fround(1.1));
//求参数平方和的平方根
console.log(Math.hypot(3,6,9),Math.sqrt(3*3+6*6+9*9));//等同于 Math.sqrt(3*3+6*6+9*9)
console.log(Math.sqrt(9));
 
console.log('100的对数是:',Math.exp(100));
console.log('100的对数-1是:',Math.expm1(100));
console.log('100的对数是:',Math.log(100));
console.log('100的对数是:',Math.log(1+100));
console.log('100的对数-1是:',Math.log1p(100));//log1p(x) = log(1+x)  x小-1返回NaN
console.log('100的对数-1是:',Math.log10(100));//返回以10为底数的x的对数  这里x为100 x小0返回NaN
console.log('100的对数-1是:',Math.log2(100));//返回以2为底数的x的对数  这里x为100 x小0返回NaN
 
//三角函数
let num=180;
console.log(Math.sinh(num));//双曲正弦
console.log(Math.cosh(num));//双曲余弦
console.log(Math.tanh(num));//双曲正切
console.log(Math.asinh(num));//反双曲正弦
console.log(Math.acosh(num));//反双曲余弦
console.log(Math.atanh(num));//反双曲正切
 
//值正负判断
//console.log(Math.signbit(-99)); //未支持
 
console.log('计算2的6次方',2**6);//**为指数运算符
//BigInt数据类型使用,计算超过2的53次方的数据,后缀加上n
const max = BigInt(Number.MAX_SAFE_INTEGER);
const two = 2n;
const result = max + two;
console.log(result);
 
 

BigInt数据类型支持,计算超出2的53次方的数值