将1234567890转换成1,234,567,890 每3位用逗号隔开的形式 PHP千分位

$num = 1234567890;
echo number_format($num);
//1,234,567,890
echo number_format($num,2);
//1,234,567,890.00
echo number_format($num,2,‘-‘,‘‘);
//1,234,567,890-00

$num = 1234567890;

function thousandsSplit($num){
    //反转字符串 0987654321
    $num = strrev($num);
    //使用逗号分割字符串 098,765,432,1,
    $num = chunk_split($num, 3, ‘,‘);
    //再次反转字符串  ,1,234,567,890
    $num = strrev($num);
    //去除最左边的逗号  1,234,567,890
    $num = ltrim($num, ‘,‘);
    echo $num;
    //输出 1,234,567,890
}