格式化字节数

[varHarrie]

function clamp (value: number, min: number, max: number) {
  return Math.max(min, Math.min(max, value))
}

function formatBytes(bytes: number) {
  const units = ['Bytes', 'KB', 'MB', /** 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB' */];

  const k = 1024;
  const i = clamp(Math.floor(Math.log(bytes) / Math.log(k)), 0, units.length - 1);
  const v = parseFloat((bytes / Math.pow(k, i)).toFixed(2))

  return `${v} ${units[i]}`;
}

console.log(formatBytes(0));        // 0 Bytes
console.log(formatBytes(1024));     // 1 KB
console.log(formatBytes(20000000)); // 19.07 MB