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
我认为这是一个解决方案。
var unitlist = ["","K","M","G"]; function formatnumber(number){ let sign = Math.sign(number); let unit = 0; while(Math.abs(number) > 1000) { unit = unit + 1; number = Math.floor(Math.abs(number) / 100)/10; } console.log(sign*Math.abs(number) + unitlist[unit]); } formatnumber(999); formatnumber(1234); formatnumber(12345); formatnumber(123456); formatnumber(1234567); formatnumber(12345678); formatnumber(-999); formatnumber(-1234); formatnumber(-12345); formatnumber(-123456); formatnumber(-1234567); formatnumber(-12345678);
其他回答
以下是我对韦伦·弗林的回答的看法。这将删除.0并修复当层不是整数时的未定义。
const SI_SYMBOL = ['', 'k', 'M', 'G', 'T', 'P', 'E'];
abbreviateNumber(num) {
const tier = Math.floor(Math.log10(num) / 3) || 0;
let result = '' + num;
// if zero, we don't need a suffix
if (tier > 0) {
// get suffix and determine scale
const suffix = SI_SYMBOL[tier];
const scale = Math.pow(10, tier * 3);
// scale the number
const scaled = num / scale;
// format number and add suffix
result = scaled.toFixed(1).replace('.0', '') + suffix;
}
return result;
}
您可以使用模仿Python高级字符串格式化PEP3101的d3格式包:
var f = require('d3-format')
console.log(f.format('.2s')(2500)) // displays "2.5k"
function transform(value,args) {
const suffixes = ['K', 'M', 'B', 'T', 'P', 'E'];
if (!value) {
return null;
}
if (Number.isNaN(value)) {
return null;
}
if (value < 1000) {
return value;
}
const exp = Math.floor(Math.log(value) / Math.log(1000));
const returnValue = (value / Math.pow(1000, exp)).toFixed(args) + suffixes[exp - 1];
return returnValue;
}
变换(9999 2)
/ /“10.00 k”
/**
* Shorten number to thousands, millions, billions, etc.
* http://en.wikipedia.org/wiki/Metric_prefix
*
* @param {number} num Number to shorten.
* @param {number} [digits=0] The number of digits to appear after the decimal point.
* @returns {string|number}
*
* @example
* // returns '12.5k'
* shortenLargeNumber(12543, 1)
*
* @example
* // returns '-13k'
* shortenLargeNumber(-12567)
*
* @example
* // returns '51M'
* shortenLargeNumber(51000000)
*
* @example
* // returns 651
* shortenLargeNumber(651)
*
* @example
* // returns 0.12345
* shortenLargeNumber(0.12345)
*/
function shortenLargeNumber(num, digits) {
var units = ['k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'],
decimal;
for(var i=units.length-1; i>=0; i--) {
decimal = Math.pow(1000, i+1);
if(num <= -decimal || num >= decimal) {
return +(num / decimal).toFixed(digits) + units[i];
}
}
return num;
}
谢谢@Cos的评论,我删除了Math。round10依赖。
Waylon flynn的答案的修改版本,支持负指数:
function metric(number) { const SI_SYMBOL = [ ["", "k", "M", "G", "T", "P", "E"], // + ["", "m", "μ", "n", "p", "f", "a"] // - ]; const tier = Math.floor(Math.log10(Math.abs(number)) / 3) | 0; const n = tier < 0 ? 1 : 0; const t = Math.abs(tier); const scale = Math.pow(10, tier * 3); return { number: number, symbol: SI_SYMBOL[n][t], scale: scale, scaled: number / scale } } function metric_suffix(number, precision) { const m = metric(number); return (typeof precision === 'number' ? m.scaled.toFixed(precision) : m.scaled) + m.symbol; } for (var i = 1e-6, s = 1; i < 1e7; i *= 10, s *= -1) { // toggles sign in each iteration console.log(metric_suffix(s * (i + i / 5), 1)); } console.log(metric(0));
预期的输出:
1.2μ
-12.0μ
120.0μ
-1.2m
12.0m
-120.0m
1.2
-12.0
120.0
-1.2k
12.0k
-120.0k
1.2M
{ number: 0, symbol: '', scale: 1, scaled: 0 }