我需要显示一个货币值的格式1K等于一千,或1.1K, 1.2K, 1.9K等,如果它不是一个偶数千,否则如果低于一千,显示正常500,100,250等,使用JavaScript格式化的数字?


当前回答

一个简短的替代方案:

function nFormatter(num) { const format = [ { value: 1e18, symbol: 'E' }, { value: 1e15, symbol: 'P' }, { value: 1e12, symbol: 'T' }, { value: 1e9, symbol: 'G' }, { value: 1e6, symbol: 'M' }, { value: 1e3, symbol: 'k' }, { value: 1, symbol: '' }, ]; const formatIndex = format.findIndex((data) => num >= data.value); console.log(formatIndex) return (num / format[formatIndex === -1? 6: formatIndex].value).toFixed(2) + format[formatIndex === -1?6: formatIndex].symbol; }

其他回答

一个简短的替代方案:

function nFormatter(num) { const format = [ { value: 1e18, symbol: 'E' }, { value: 1e15, symbol: 'P' }, { value: 1e12, symbol: 'T' }, { value: 1e9, symbol: 'G' }, { value: 1e6, symbol: 'M' }, { value: 1e3, symbol: 'k' }, { value: 1, symbol: '' }, ]; const formatIndex = format.findIndex((data) => num >= data.value); console.log(formatIndex) return (num / format[formatIndex === -1? 6: formatIndex].value).toFixed(2) + format[formatIndex === -1?6: formatIndex].symbol; }

如果你喜欢,就把功劳归于韦伦·弗林

这比他处理负数和“。0”的情况。

循环和“如果”情况越少,IMO就越好。

function abbreviateNumber(number) {
    const SI_POSTFIXES = ["", "k", "M", "G", "T", "P", "E"];
    const sign = number < 0 ? '-1' : '';
    const absNumber = Math.abs(number);
    const tier = Math.log10(absNumber) / 3 | 0;
    // if zero, we don't need a prefix
    if(tier == 0) return `${absNumber}`;
    // get postfix and determine scale
    const postfix = SI_POSTFIXES[tier];
    const scale = Math.pow(10, tier * 3);
    // scale the number
    const scaled = absNumber / scale;
    const floored = Math.floor(scaled * 10) / 10;
    // format number and add postfix as suffix
    let str = floored.toFixed(1);
    // remove '.0' case
    str = (/\.0$/.test(str)) ? str.substr(0, str.length - 2) : str;
    return `${sign}${str}${postfix}`;
}

jsFiddle测试用例-> https://jsfiddle.net/qhbrz04o/9/

通过消除@martin-sznapka解决方案中的循环,您将减少40%的执行时间。

function formatNum(num,digits) {
    let units = ['k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'];
    let floor = Math.floor(Math.abs(num).toString().length / 3);
    let value=+(num / Math.pow(1000, floor))
    return value.toFixed(value > 1?digits:2) + units[floor - 1];

}

速度测试(200000随机样本)从这个线程不同的解决方案

Execution time: formatNum          418  ms
Execution time: kFormatter         438  ms it just use "k" no "M".."T" 
Execution time: beautify           593  ms doesnt support - negatives
Execution time: shortenLargeNumber 682  ms    
Execution time: Intl.NumberFormat  13197ms 

听起来这应该对你有用:

函数 kFormatter(num) { 返回 Math.abs(num) > 999 ?Math.sign(num)*((Math.abs(num)/1000).toFixed(1)) + 'k' : Math.sign(num)*Math.abs(num) } console.log(kFormatter(1200));1.2k console.log(kFormatter(-1200));-1.2k console.log(kFormatter(900));900 console.log(kFormatter(-900));-900

进一步改进@Yash的回答,支持负数:

function nFormatter(num) {
    isNegative = false
    if (num < 0) {
        isNegative = true
    }
    num = Math.abs(num)
    if (num >= 1000000000) {
        formattedNumber = (num / 1000000000).toFixed(1).replace(/\.0$/, '') + 'G';
    } else if (num >= 1000000) {
        formattedNumber =  (num / 1000000).toFixed(1).replace(/\.0$/, '') + 'M';
    } else  if (num >= 1000) {
        formattedNumber =  (num / 1000).toFixed(1).replace(/\.0$/, '') + 'K';
    } else {
        formattedNumber = num;
    }   
    if(isNegative) { formattedNumber = '-' + formattedNumber }
    return formattedNumber;
}

nFormatter(-120000)
"-120K"
nFormatter(120000)
"120K"