我得到这段代码通过PHP隐蔽大小字节。

现在我想使用JavaScript将这些大小转换为人类可读的大小。我尝试将这段代码转换为JavaScript,看起来像这样:

function formatSizeUnits(bytes){
  if      (bytes >= 1073741824) { bytes = (bytes / 1073741824).toFixed(2) + " GB"; }
  else if (bytes >= 1048576)    { bytes = (bytes / 1048576).toFixed(2) + " MB"; }
  else if (bytes >= 1024)       { bytes = (bytes / 1024).toFixed(2) + " KB"; }
  else if (bytes > 1)           { bytes = bytes + " bytes"; }
  else if (bytes == 1)          { bytes = bytes + " byte"; }
  else                          { bytes = "0 bytes"; }
  return bytes;
}

这是正确的做法吗?有没有更简单的方法?


当前回答

根据al冰岛m的答案,我在小数点后去掉了0:

function formatBytes(bytes, decimals) {
    if(bytes== 0)
    {
        return "0 Byte";
    }
    var k = 1024; //Or 1 kilo = 1000
    var sizes = ["Bytes", "KB", "MB", "GB", "TB", "PB"];
    var i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(decimals)) + " " + sizes[i];
}

其他回答

这是一个坚实的有效的方法来转换字节。你唯一需要做的就是安装mathjs库进行精确的计算。复制粘贴即可。

import { multiply, divide, round } from "mathjs";

class Size {
  constructor(value, unit) {
    this.value = value;
    this.unit = unit.toUpperCase();
  }
}

async function byteToSize(bytes) {
  const B = 1;
  const KB = multiply(B, 1024);
  const MB = multiply(KB, 1024);
  const GB = multiply(MB, 1024);
  const TB = multiply(GB, 1024);
  const PB = multiply(TB, 1024);

  if (bytes <= KB) {
    // @returns BYTE

    const result = round(divide(bytes, B));
    const unit = `B`;

    return new Size(result, unit);
  }

  if (bytes <= MB) {
    // @returns KILOBYTE

    const result = round(divide(bytes, KB));
    const unit = `KB`;

    return new Size(result, unit);
  }

  if (bytes <= GB) {
    // @returns MEGABYTE

    const result = round(divide(bytes, MB));
    const unit = `MB`;

    return new Size(result, unit);
  }

  if (bytes <= TB) {
    // @returns GIGABYTE

    const result = round(divide(bytes, GB));
    const unit = `GB`;

    return new Size(result, unit);
  }

  if (bytes <= PB) {
    // @returns TERABYTE

    const result = divide(bytes, TB).toFixed(2);
    const unit = `TB`;

    return new Size(result, unit);
  }

  if (bytes >= PB) {
    // @returns PETABYTE

    const result = divide(bytes, PB).toFixed(2);
    const unit = `PB`;

    return new Size(result, unit);
  }
}

var大小=[“字节”,“知识库”,“m”,“g”,“结核”,“铅”、“海尔哥哥”,“ZB”,“YB”); 函数formatBytes(字节,小数){ For (var I = 0, r = bytes, b = 1024;R > b;I ++) r /= b; 返回' ${parseFloat(r.toFixed(decimal))} ${SIZES[i]} '; }

由此可见:(来源)


Unminified and es6’ed:(社区)

function formatBytes(bytes, decimals = 2) { if (!+bytes) return '0 Bytes' const k = 1024 const dm = decimals < 0 ? 0 : decimals const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'] const i = Math.floor(Math.log(bytes) / Math.log(k)) return `${parseFloat((bytes / Math.pow(k, i)).toFixed(dm))} ${sizes[i]}` } // Demo code document.body.innerHTML += `<input type="text" oninput="document.querySelector('p').innerHTML=formatBytes(this.value)" value="1000"><p>1000 Bytes</p>`

简化版(由StackOverflow社区提供,由JSCompress提供)

function formatBytes(a,b=2){if(!+a)return"0 Bytes";const c=0>b?0:b,d=Math.floor(Math.log(a)/Math.log(1024));return`${parseFloat((a/Math.pow(1024,d)).toFixed(c))} ${["Bytes","KB","MB","GB","TB","PB","EB","ZB","YB"][d]}`}

用法:

// formatBytes(bytes, decimals)

formatBytes(1024)       // 1 KB
formatBytes('1024')     // 1 KB
formatBytes(1234)       // 1.21 KB
formatBytes(1234, 3)    // 1.205 KB
formatBytes(0)          // 0 Bytes
formatBytes('0')        // 0 Bytes

PS:更改k = 1000或大小=["…如你所愿(比特或字节)

使用位操作将是一个更好的解决方案。试试这个

function formatSizeUnits(bytes)
{
    if ( ( bytes >> 30 ) & 0x3FF )
        bytes = ( bytes >>> 30 ) + '.' + ( bytes & (3*0x3FF )) + 'GB' ;
    else if ( ( bytes >> 20 ) & 0x3FF )
        bytes = ( bytes >>> 20 ) + '.' + ( bytes & (2*0x3FF ) ) + 'MB' ;
    else if ( ( bytes >> 10 ) & 0x3FF )
        bytes = ( bytes >>> 10 ) + '.' + ( bytes & (0x3FF ) ) + 'KB' ;
    else if ( ( bytes >> 1 ) & 0x3FF )
        bytes = ( bytes >>> 1 ) + 'Bytes' ;
    else
        bytes = bytes + 'Byte' ;
    return bytes ;
}

根据al冰岛m的答案,我在小数点后去掉了0:

function formatBytes(bytes, decimals) {
    if(bytes== 0)
    {
        return "0 Byte";
    }
    var k = 1024; //Or 1 kilo = 1000
    var sizes = ["Bytes", "KB", "MB", "GB", "TB", "PB"];
    var i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(decimals)) + " " + sizes[i];
}