javaScript格式化文件大小

///格式化文件大小
function formatFileSize(fileSize) {
if (fileSize < 1024) {
return fileSize + 'B';
} else if (fileSize < (1024*1024)) {
var temp = fileSize / 1024;
temp = temp.toFixed(2);
return temp + 'KB';
} else if (fileSize < (1024*1024*1024)) {
var temp = fileSize / (1024*1024);
temp = temp.toFixed(2);
return temp + 'MB';
} else {
var temp = fileSize / (1024*1024*1024);
temp = temp.toFixed(2);
return temp + 'GB';
}
}