while( $low <= $high )
 {
  if ($P[$current] == $t) {
   return true;
  }
  if ($t < $P[$current]) {
   $high = $current-1;
  }
  else {
   $low = $current+1
  }
  $current = floor($high + $low)/2
 }
 return false;

	$x = $P[$t];
	$mid = ($low+$high)/2;
	if($low<$high) {
		if($x[$mid] > $current) {
			return binarySearch($t, $P, $low, $mid, $current); 
		} else if($x[$mid] < $current) {
			return binarySearch($t, $P, $mid+1, $high, $current);			
		}
	}
	return $x[$mid];

	"cat" => [1,6,7],
	"dog" => [1,2,23,25,27,50]

	$i = (int) (($low + $high) / 2);
	while(true){
		if ($current<$P[$t][$i]) {
			if($high == $i) return $P[$t][$i];
			$high = $i;
			$i=(int) (($i+$low)/2);
		}
		else if ($P[$t][$i] < $current){
			if ($low == $i) return $P[$t][$i+1];
			$low = $i;
			$i=(int) (($i+$high)/2);
		}
	}

	if ($high >= $low) {
 
        $mid = $low + ($high - $low) / 2; 
  
        // If an index after $current is present  
        if ($P[$t][$mid] > $current && $P[$t][$mid-1] < $current)  
            return $P[$t][$mid]; 
  
        // Search only left subarray 
        // if current index is smaller than 
        // the midpoint's index 
        if ($P[$t][$mid] > $current)  
            return binarySearch($t, $P, $low,  
                                $mid - 1, $current); 
  
        // Search only right subarray 
        // if current index is larger than 
        // the midpoint's index
        return binarySearch($t,$P, $mid + 1,  
                            $high, $current); 
		} 
  

 		// when no index in array satisfying the conditions  
		return -1; 
		}// end of function  

 <?php

  function binarySearch($t, $p, $low, $high, $current){
    // Find the array of the term
    $arr = $p[$t];
    /* Start the while loop till $low is less than equal to $high.
    */
    while($low <= $high){
        // Find middle position of the array
        $avg = floor(($low+$high)/2);
        // If we find something greater than
        // equal to $current move down
        if($arr[$avg]>=$current){
            $high = $avg-1;
        }else{
        // Else move up in the array
            $low = $avg+1;
        }
    }
    // return the value which is equal or
    // first greater than the $current
    return $arr[$low];

    $t = "dog";
    $P = [
       "cat" => [1, 6, 7],
       "dog" => [1 ,2, 23, 25, 27, 50]
    ];
    echo  binarySearch($t, $P, 1, 5, 15);

  "cat" =>[1,6,7],
  "dog"=>[1,2,23,25,27,50]];

  if($high-$low == 1)
  {
    return ($P[$t][$high]);
  }
  while($low < $high)
  {
    $mid = (int)(($high+$low)/2);

    if ($P[$t][$mid] < $current)
    {
      return binarySearch($t,$P,$mid,$high,$current);
    }
    else
    {
      return binarySearch($t,$P,$low,$mid,$current);
    }

  }

    while($high - $low > 1) {
        $mid = (int)(($low + $high)/2);
        if(($P[$t][$mid] > $current)) {
            $high = $mid;
        } else {
            $low = $mid;
        }
    }
    if($high - $low == 1) {
        if($P[$t][$low] <= $current) {
            if($P[$t][$high] > $current) {
                return $P[$t][$high];
            }
        }
    }
    return -1;

   "cat" => [1, 6, 7],
   "dog" => [1 ,2, 23, 25, 27, 50]

	// check for empty array
    if (count($P) === 0) return 0;
     
    while ($low <= $high) {
         
        // compute middle index
        $mid = floor(($low + $high) / 2);
  
        // element found at mid
        if($P[$t][$mid] >= $current && $P[$t][$mid - 1] < $current) {
            return $P[$t][$mid];
        }
 
        if ($current < $P[$t][$mid]) {
            // search the left side of the array
            $high = $mid -1;
        }
        else {
            // search the right side of the array
            $low = $mid + 1;
        }
    }
     
    // If we reach here the element doesnt exist
    return 0;