PHP入门教程之数学运算技巧总结

<?php// $a = '5';// $b = 7+$a;// echo $b;  $a = 'a';  $b = 7+$a;  echo $b;?>

<?php  $a = 10.0;  //is_int -- 检测变量是否是整数  if(is_int($a)) {    echo '通过';  }else{    echo '不通过';  }?>

<?php  $a = 10.0;  //is_int -- 检测变量是否是整数  if(is_int($a)) {    echo '通过';  }else{    echo '不通过';  }?>

<?php  //rand -- 产生一个随机整数  //echo rand(0,10);  //echo mt_rand(0,100);  //echo getrandmax();//最大数32767  //echo mt_getrandmax();//最大数2147483647?>

<?php// $i = 123456789.4454;// $b = number_format($i,2);// echo $b;  //123,456,789.45  $i = 12378456.456789;  $b = number_format($i,2,'#','@');  echo $b;//12@378@456#46?>

<?php// $a = -6;// echo abs($a);//绝对值// $b = 5.66;// echo floor($b);//舍去法取整// echo round($b);//四舍五入  echo min(1,23,456,87,45,7,54);//1 求最小值或数组中最小值  echo max(1,23,456,87,45,7,54);//456 求最大值或数组中最大值  echo pi();//3.14159265359  echo pow(2,6);//64?>