就像 Stackoverlow 声誉四舍五入一样,我希望对货币做同样的事情
$1,000 => 1k
$1,000,000 => 1m
如何在 JavaScript 中(最好是 jQuery)实现这一点?
这是一个简单的函数来做到这一点:
function abbrNum(number, decPlaces) {
// 2 decimal places => 100, 3 => 1000, etc
decPlaces = Math.pow(10, decPlaces);
// Enumerate number abbreviations
var abbrev = ["k", "m", "b", "t"];
// Go through the array backwards, so we do the largest first
for (var i = abbrev.length - 1; i >= 0; i--) {
// Convert array index to "1000", "1000000", etc
var size = Math.pow(10, (i + 1) * 3);
// If the number is bigger or equal do the abbreviation
if (size <= number) {
// Here, we multiply by decPlaces, round, and then divide by decPlaces.
// This gives us nice rounding to a particular decimal place.
number = Math.round(number * decPlaces / size) / decPlaces;
// Handle special case where we round up to the next abbreviation
if ((number == 1000) && (i < abbrev.length - 1)) {
number = 1;
i++;
}
// Add the letter for the abbreviation
number += abbrev[i];
// We are done... stop
break;
}
}
return number;
}
console.log(abbrNum(1200, 3))
输出:
abbrNum(12 , 1) => 12
abbrNum(0 , 2) => 0
abbrNum(1234 , 0) => 1k
abbrNum(34567 , 2) => 34.57k
abbrNum(918395 , 1) => 918.4k
abbrNum(2134124 , 2) => 2.13m
abbrNum(47475782130 , 2) => 47.48b
var floor=Math.floor, abs=Math.abs, log=Math.log, round=Math.round, min=Math.min;
var abbrev = ['k', 'Mil', 'Bil']; // abbreviations in steps of 1000x; extensible if need to edit
function rnd(n, precision) {
var prec = 10**precision;
return round(n*prec)/prec;
}
function format(n) {
var base = floor(log(abs(n))/log(1000));
var suffix = abbrev[min(abbrev.length-1, base-1)];
base = abbrev.indexOf(suffix) + 1;
return suffix ? rnd(n/1000**base,2)+suffix : ''+n;
}
演示:
> tests = [-1001, -1, 0, 1, 2.5, 999, 1234,
1234.5, 1000001, 10**9, 10**12]
> tests.forEach(function(x){ console.log(x,format(x)) })
-1001 "-1k"
-1 "-1"
0 "0"
1 "1"
2.5 "2.5"
999 "999"
1234 "1.23k"
1234.5 "1.23k"
1000001 "1Mil"
1000000000 "1Bil"
1000000000000 "1000Bil"