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?
这里有一句话:
val => ['Bytes','Kb','Mb','Gb','Tb'][Math.floor(Math.log2(val)/10)]
甚至:
v => 'BKMGT'[~~(Math.log2(v)/10)]
与数:
function shortenBytes(n) {
const k = n > 0 ? Math.floor((Math.log2(n)/10)) : 0;
const rank = (k > 0 ? 'KMGT'[k - 1] : '') + 'b';
const count = Math.floor(n / Math.pow(1024, k));
return count + rank;
}
我只是想分享我的想法。我遇到了这个问题，所以我的解决方案是这样的。这将把低单位转换为高单位，反之亦然，只需提供参数toUnit和fromUnit
export function fileSizeConverter(size: number, fromUnit: string, toUnit: string ): number | string {
const units: string[] = ['B', 'KB', 'MB', 'GB', 'TB'];
const from = units.indexOf(fromUnit.toUpperCase());
const to = units.indexOf(toUnit.toUpperCase());
const BASE_SIZE = 1024;
let result: number | string = 0;
if (from < 0 || to < 0 ) { return result = 'Error: Incorrect units'; }
result = from < to ? size / (BASE_SIZE ** to) : size * (BASE_SIZE ** from);
return result.toFixed(2);
}
我从这里得到了灵感
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!
