这个解决方案建立在以前的解决方案的基础上，但同时考虑了公制和二进制单位:

function formatBytes(bytes, decimals, binaryUnits) {
    if(bytes == 0) {
        return '0 Bytes';
    }
    var unitMultiple = (binaryUnits) ? 1024 : 1000; 
    var unitNames = (unitMultiple === 1024) ? // 1000 bytes in 1 Kilobyte (KB) or 1024 bytes for the binary version (KiB)
        ['Bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB']: 
        ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
    var unitChanges = Math.floor(Math.log(bytes) / Math.log(unitMultiple));
    return parseFloat((bytes / Math.pow(unitMultiple, unitChanges)).toFixed(decimals || 0)) + ' ' + unitNames[unitChanges];
}

例子:

formatBytes(293489203947847, 1);    // 293.5 TB
formatBytes(1234, 0);   // 1 KB
formatBytes(4534634523453678343456, 2); // 4.53 ZB
formatBytes(4534634523453678343456, 2, true));  // 3.84 ZiB
formatBytes(4566744, 1);    // 4.6 MB
formatBytes(534, 0);    // 534 Bytes
formatBytes(273403407, 0);  // 273 MB

function bytes2Size(byteVal){
    var units=["Bytes", "KB", "MB", "GB", "TB"];
    var kounter=0;
    var kb= 1024;
    var div=byteVal/1;
    while(div>=kb){
        kounter++;
        div= div/kb;
    }
    return div.toFixed(1) + " " + units[kounter];
}

我让算法快了7倍(就像忍者一样):

function rafaelFormatBytes(number){ if(number == null || number === undefined || number <= 0) { return '0 Bytes'; } var scaleCounter = 0; var scaleInitials = [' Bytes',' KB',' MB',' GB',' TB',' PB',' EB',' ZB',' YB']; while (number >= 1024 && scaleCounter < scaleInitials.length - 1){ number /= 1024; scaleCounter++; } if(scaleCounter >= scaleInitials.length) scaleCounter = scaleInitials.length - 1; var compactNumber = number.toFixed(2) .replace(/\.?0+$/,'') .replace(/\B(?=(\d{3})+(?!\d))/g, ","); compactNumber += scaleInitials[scaleCounter]; return compactNumber.trim(); } var testNum = 0; var startTime, endTime; function start() { startTime = new Date(); }; function end() { endTime = new Date(); var timeDiff = endTime - startTime; //in ms // strip the ms timeDiff /= 1000; // get seconds var seconds = Math.round(timeDiff, 5); console.log(timeDiff + " seconds"); } function formatBytes(a,b=2,k=1024){with(Math){let d=floor(log(a)/log(k));return 0==a?"0 Bytes":parseFloat((a/pow(k,d)).toFixed(max(0,b)))+" "+["Bytes","KB","MB","GB","TB","PB","EB","ZB","YB"][d]}} console.log(formatBytes(1000000000000000000000000000)); console.log(rafaelFormatBytes(1000000000000000000000000000)); start(); for(i=0; i<100000; i++){ formatBytes(1000000000000000); } end(); start(); for(i=0; i<100000; i++){ rafaelFormatBytes(1000000000000000); } end();

．.． 输出:

827.18 YB
827.18 YB
0.293 seconds
0.039 seconds

耶稣基督!

我最初在一个文件上传项目中使用@ al冰岛jm的答案，但最近遇到了一个问题，一个文件是0.98kb，但读取为1.02mb。下面是我现在使用的更新代码。

function formatBytes(bytes){
  var kb = 1024;
  var ndx = Math.floor( Math.log(bytes) / Math.log(kb) );
  var fileSizeTypes = ["bytes", "kb", "mb", "gb", "tb", "pb", "eb", "zb", "yb"];

  return {
    size: +(bytes / kb / kb).toFixed(2),
    type: fileSizeTypes[ndx]
  };
}

在像这样添加文件之后，上面的函数将被调用

// In this case `file.size` equals `26060275` 
formatBytes(file.size);
// returns `{ size: 24.85, type: "mb" }`

当然，Windows读取的文件为24.8mb，但我对额外的精度很满意。

我正在更新@ al冰岛的答案。由于小数点对于1,2位数的数字很重要，所以我舍入了第一个小数点并保留第一个小数点。对于3位数的数字，我舍入个位数，忽略所有小数点后的位置。

getMultiplers : function(bytes){
    var unit = 1000 ;
    if (bytes < unit) return bytes ;
    var exp = Math.floor(Math.log(bytes) / Math.log(unit));
    var pre = "kMGTPE".charAt(exp-1);
    var result = bytes / Math.pow(unit, exp);
    if(result/100 < 1)
        return (Math.round( result * 10 ) / 10) +pre;
    else
        return Math.round(result) + pre;
}

你可以使用pretty-bytes库。

安装

npm install pretty-bytes

使用

import prettyBytes from 'pretty-bytes';

prettyBytes(1337);
//=> '1.34 kB'

prettyBytes(100);
//=> '100 B'

// Display with units of bits
prettyBytes(1337, {bits: true});
//=> '1.34 kbit'

// Display file size differences
prettyBytes(42, {signed: true});
//=> '+42 B'

// Localized output using German locale
prettyBytes(1337, {locale: 'de'});
//=> '1,34 kB'