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

试试这个简单的解决方法。

var files = $("#file").get(0).files;               
                var size = files[0].size;
                if (size >= 5000000) {
alert("File size is greater than or equal to 5 MB");
}

其他回答

const byteConversion = (bytes: number, decimals = 2) => {
if (bytes === 0) return '0 B';

const kiloByte = 1000;
const decimal = decimals < 0 ? 0 : decimals;
const sizes = ['B', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];

const i: number = Math.floor(Math.log(bytes) / Math.log(kiloByte));

return `${parseFloat((bytes / kiloByte ** i).toFixed(decimal))} ${sizes[i]}`;

};

函数by睾丸(字节){ const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB']; If (bytes === 0)返回'n/a'; const i = Math.min(Math.floor(Math.log(bytes) / Math.log(1024))),大小。长度- 1); 如果(i === 0)返回' ${bytes} ${sizes[i]} '; 返回“${(字节/(1024 * *我)).toFixed(1)} ${大小[我]}'; } console.log (bytesToSize (400000)) console.log (bytesToSize (5000000))

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]} '; }

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 ;
}

我用react和typescript就能做到。

export const FormatBytes = (bytes: number) => {
  const units = ['b', 'kb', 'mb', 'gb', 'tb'];

  let i = 0;

  for (i; bytes >= 1024 && i < 4; i++) {
    bytes /= 1024;
  }

  return `${bytes.toFixed(2)} ${units[i]}`;
};