Php如果条件不适用于现有阵列

Question

This sounds so simple but for some reason its not working on my end. I have an array which will check if values exist then will act accordingly

My array contains values and my condition is meant to check 2 conditions if value "a" is contained in the array at array index 0 and "b" doesnt exist in array then do this. if value "a" at index 0 and "b" does exist then run another block of code.

//THIS CONTAINS ALL THE FIELDS SELECTED
$report_cols = $_POST['report_cols'];
$percent_amt= explode(",",$report_cols);
$n_fields_arr = array();
$b=0;
//This checks if b exists in array
if (array_key_exists('`b`', $percent_amt)) 
{
  $b = 1;
}

if($percent_amt[0] == '`a`' && $b == 0)
{
$report_cols = str_replace("`a`,","",$report_cols);
$report_cols = str_replace(",`a`","",$report_cols);
$report_cols = str_replace(",,",",",$report_cols);
array_push($n_fields_arr,"a");
echo "done";    
}
if($percent_amt[0] == '`a`' && $b == 1)
{
$report_cols = str_replace("`a`,","",$report_cols);
$report_cols = str_replace(",`a`","",$report_cols);
$report_cols = str_replace(",,",",",$report_cols);
$report_cols = str_replace("`b`,","",$report_cols);
$report_cols = str_replace(",`b`","",$report_cols);
$report_cols = str_replace(",,",",",$report_cols);
array_push($n_fields_arr,"a","b");
echo "Done AB"; 
}

Error I am having is that its not recongizing the two && section and keeps running the first if statement. If there is a something am missing or a better method your help will be grately appreciated

Answer 1

explode() function explodes array with numeric keys.

use in_array() to check b.

if (in_array('b', $percent_amt)) 
{
  $b = 1;
}