用途
number_format()：
if ($n < 1000000) { // Anything less than a million $n_format = number_format($n);} else if ($n < 1000000000) { // Anything less than a billion $n_format = number_format($n / 1000000, 3) . 'M';} else { // At least a billion $n_format = number_format($n / 1000000000, 3) . 'B';}如果可以的话，我非常感谢任何自定义函数可以动态选择限制。
如果“限制”是指小数位数（精度），则很简单：
function custom_number_format($n, $precision = 3) { if ($n < 1000000) { // Anything less than a million $n_format = number_format($n); } else if ($n < 1000000000) { // Anything less than a billion $n_format = number_format($n / 1000000, $precision) . 'M'; } else { // At least a billion $n_format = number_format($n / 1000000000, $precision) . 'B'; } return $n_format;}
