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?
当与字节相关时,有两种真实的方法来表示大小,它们是SI单位(10^3)或IEC单位(2^10)。也有JEDEC,但他们的方法是模糊的和令人困惑的。我注意到其他示例有错误,例如使用KB而不是KB来表示千字节,因此我决定编写一个函数,使用当前接受的度量单位的范围来解决这些情况。
在结尾有一个格式化的地方,这将使数字看起来更好一点(至少在我看来),如果它不适合你的目的,请随意删除这个格式。
享受。
// pBytes: the size in bytes to be converted.
// pUnits: 'si'|'iec' si units means the order of magnitude is 10^3, iec uses 2^10
function prettyNumber(pBytes, pUnits) {
// Handle some special cases
if(pBytes == 0) return '0 Bytes';
if(pBytes == 1) return '1 Byte';
if(pBytes == -1) return '-1 Byte';
var bytes = Math.abs(pBytes)
if(pUnits && pUnits.toLowerCase() && pUnits.toLowerCase() == 'si') {
// SI units use the Metric representation based on 10^3 as a order of magnitude
var orderOfMagnitude = Math.pow(10, 3);
var abbreviations = ['Bytes', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
} else {
// IEC units use 2^10 as an order of magnitude
var orderOfMagnitude = Math.pow(2, 10);
var abbreviations = ['Bytes', 'KiB', 'MiB', 'GiB', 'TiB', 'PiB', 'EiB', 'ZiB', 'YiB'];
}
var i = Math.floor(Math.log(bytes) / Math.log(orderOfMagnitude));
var result = (bytes / Math.pow(orderOfMagnitude, i));
// This will get the sign right
if(pBytes < 0) {
result *= -1;
}
// This bit here is purely for show. it drops the percision on numbers greater than 100 before the units.
// it also always shows the full number of bytes if bytes is the unit.
if(result >= 99.995 || i==0) {
return result.toFixed(0) + ' ' + abbreviations[i];
} else {
return result.toFixed(2) + ' ' + abbreviations[i];
}
}
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]}`;
};
如果表示的单位小于10 KB或更大,则此解决方案包括一个小数点和一个十分位数字
const units = ['bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
function niceBytes(x){
let l = 0, n = parseInt(x, 10) || 0;
while(n >= 1024 && ++l){
n = n/1024;
}
return(n.toFixed(n < 10 && l > 0 ? 1 : 0) + ' ' + units[l]);
}
结果:
niceBytes(7) // 7 bytes
niceBytes(435) // 435 bytes
niceBytes(3398) // 3.3 KB
niceBytes(490398) // 479 KB
niceBytes(6544528) // 6.2 MB
niceBytes(23483023) // 22 MB
niceBytes(3984578493) // 3.7 GB
niceBytes(30498505889) // 28 GB
niceBytes(9485039485039445) // 8.4 PB