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
最多支持数量。MAX_SAFE_INTEGER到Number。MIN_SAFE_INTEGER
function abbreviateThousands(value) { const num = Number(value) const absNum = Math.abs(num) const sign = Math.sign(num) const numLength = Math.round(absNum).toString().length const symbol = ['K', 'M', 'B', 'T', 'Q'] const symbolIndex = Math.floor((numLength - 1) / 3) - 1 const abbrv = symbol[symbolIndex] || symbol[symbol.length - 1] let divisor = 0 if (numLength > 15) divisor = 1e15 else if (numLength > 12) divisor = 1e12 else if (numLength > 9) divisor = 1e9 else if (numLength > 6) divisor = 1e6 else if (numLength > 3) divisor = 1e3 else return num return `${((sign * absNum) / divisor).toFixed(divisor && 1)}${abbrv}` } console.log(abbreviateThousands(234523452345)) // 234.5b (billion) console.log(abbreviateThousands(Number.MIN_SAFE_INTEGER)) // -9.0q (quadrillion)
其他回答
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}${postfix}`;
}
jsFiddle测试用例-> https://jsfiddle.net/qhbrz04o/9/
通过消除@martin-sznapka解决方案中的循环,您将减少40%的执行时间。
function formatNum(num,digits) {
let units = ['k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'];
let floor = Math.floor(Math.abs(num).toString().length / 3);
let value=+(num / Math.pow(1000, floor))
return value.toFixed(value > 1?digits:2) + units[floor - 1];
}
速度测试(200000随机样本)从这个线程不同的解决方案
Execution time: formatNum 418 ms
Execution time: kFormatter 438 ms it just use "k" no "M".."T"
Execution time: beautify 593 ms doesnt support - negatives
Execution time: shortenLargeNumber 682 ms
Execution time: Intl.NumberFormat 13197ms
Waylon flynn的答案的修改版本,支持负指数:
function metric(number) { const SI_SYMBOL = [ ["", "k", "M", "G", "T", "P", "E"], // + ["", "m", "μ", "n", "p", "f", "a"] // - ]; const tier = Math.floor(Math.log10(Math.abs(number)) / 3) | 0; const n = tier < 0 ? 1 : 0; const t = Math.abs(tier); const scale = Math.pow(10, tier * 3); return { number: number, symbol: SI_SYMBOL[n][t], scale: scale, scaled: number / scale } } function metric_suffix(number, precision) { const m = metric(number); return (typeof precision === 'number' ? m.scaled.toFixed(precision) : m.scaled) + m.symbol; } for (var i = 1e-6, s = 1; i < 1e7; i *= 10, s *= -1) { // toggles sign in each iteration console.log(metric_suffix(s * (i + i / 5), 1)); } console.log(metric(0));
预期的输出:
1.2μ
-12.0μ
120.0μ
-1.2m
12.0m
-120.0m
1.2
-12.0
120.0
-1.2k
12.0k
-120.0k
1.2M
{ number: 0, symbol: '', scale: 1, scaled: 0 }
我决定在这里扩展@Novellizator的答案,以满足我的需求。我想要一个灵活的函数来处理我的大部分格式化需求,而不需要外部库。
特性
选择使用顺序后缀(k, M等) 选项指定要使用的订单后缀的自定义列表 选项来约束最小和最大顺序 控制小数点后的位数 自动顺序分隔逗号 可选百分比或美元格式 控制在非数字输入的情况下返回什么 适用于负数和无穷数
例子
let x = 1234567.8;
formatNumber(x); // '1,234,568'
formatNumber(x, {useOrderSuffix: true}); // '1M'
formatNumber(x, {useOrderSuffix: true, decimals: 3, maxOrder: 1}); // '1,234.568k'
formatNumber(x, {decimals: 2, style: '$'}); // '$1,234,567.80'
x = 10.615;
formatNumber(x, {style: '%'}); // '1,062%'
formatNumber(x, {useOrderSuffix: true, decimals: 1, style: '%'}); // '1.1k%'
formatNumber(x, {useOrderSuffix: true, decimals: 5, style: '%', minOrder: 2}); // '0.00106M%'
formatNumber(-Infinity); // '-∞'
formatNumber(NaN); // ''
formatNumber(NaN, {valueIfNaN: NaN}); // NaN
函数
/*
* Return the given number as a formatted string. The default format is a plain
* integer with thousands-separator commas. The optional parameters facilitate
* other formats:
* - decimals = the number of decimals places to round to and show
* - valueIfNaN = the value to show for non-numeric input
* - style
* - '%': multiplies by 100 and appends a percent symbol
* - '$': prepends a dollar sign
* - useOrderSuffix = whether to use suffixes like k for 1,000, etc.
* - orderSuffixes = the list of suffixes to use
* - minOrder and maxOrder allow the order to be constrained. Examples:
* - minOrder = 1 means the k suffix should be used for numbers < 1,000
* - maxOrder = 1 means the k suffix should be used for numbers >= 1,000,000
*/
function formatNumber(number, {
decimals = 0,
valueIfNaN = '',
style = '',
useOrderSuffix = false,
orderSuffixes = ['', 'k', 'M', 'B', 'T'],
minOrder = 0,
maxOrder = Infinity
} = {}) {
let x = parseFloat(number);
if (isNaN(x))
return valueIfNaN;
if (style === '%')
x *= 100.0;
let order;
if (!isFinite(x) || !useOrderSuffix)
order = 0;
else if (minOrder === maxOrder)
order = minOrder;
else {
const unboundedOrder = Math.floor(Math.log10(Math.abs(x)) / 3);
order = Math.max(
0,
minOrder,
Math.min(unboundedOrder, maxOrder, orderSuffixes.length - 1)
);
}
const orderSuffix = orderSuffixes[order];
if (order !== 0)
x /= Math.pow(10, order * 3);
return (style === '$' ? '$' : '') +
x.toLocaleString(
'en-US',
{
style: 'decimal',
minimumFractionDigits: decimals,
maximumFractionDigits: decimals
}
) +
orderSuffix +
(style === '%' ? '%' : '');
}
韦伦·弗林解决方案的2020版。
const SI_SYMBOLS = ["", "k", "M", "G", "T", "P", "E"];
const abbreviateNumber = (number, minDigits, maxDigits) => {
if (number === 0) return number;
// determines SI symbol
const tier = Math.floor(Math.log10(Math.abs(number)) / 3);
// get suffix and determine scale
const suffix = SI_SYMBOLS[tier];
const scale = 10 ** (tier * 3);
// scale the number
const scaled = number / scale;
// format number and add suffix
return scaled.toLocaleString(undefined, {
minimumFractionDigits: minDigits,
maximumFractionDigits: maxDigits,
}) + suffix;
};
Tests and examples: const abbreviateNumberFactory = (symbols) => ( (number, minDigits, maxDigits) => { if (number === 0) return number; // determines SI symbol const tier = Math.floor(Math.log10(Math.abs(number)) / 3); // get suffix and determine scale const suffix = symbols[tier]; const scale = 10 ** (tier * 3); // scale the number const scaled = number / scale; // format number and add suffix return scaled.toLocaleString(undefined, { minimumFractionDigits: minDigits, maximumFractionDigits: maxDigits, }) + suffix; } ); const SI_SYMBOLS = ["", "k", "M", "G", "T", "P", "E"]; const SHORT_SYMBOLS = ["", "K", "M", "B", "T", "Q"]; const LONG_SYMBOLS = ["", " thousand", " million", " billion", " trillion", " quadrillion"]; const abbreviateNumberSI = abbreviateNumberFactory(SI_SYMBOLS); const abbreviateNumberShort = abbreviateNumberFactory(SHORT_SYMBOLS); const abbreviateNumberLong = abbreviateNumberFactory(LONG_SYMBOLS); const tests = [1e5, -9e7, [1009999.999, 2], [245345235.34513, 1, 1], [-72773144123, 3] ]; const functions = { abbreviateNumberSI, abbreviateNumberShort, abbreviateNumberLong, }; tests.forEach((test) => { const testValue = Array.isArray(test) ? test : [test]; Object.entries(functions).forEach(([key, func]) => { console.log(`${key}(${testValue.join(', ')}) = ${func(...testValue)}`); }); });