Summary of how to use php array search function

This time I will bring you a summary of how to use the php array search function. What are the precautions when using the php array search function? The following is a practical case, let’s take a look.

php always uses a foreach loop to find whether the specified value exists in the array.
There is a better way, you can use the three built-in array functions of PHP to find whether the specified value exists in the array. These three arrays are in_array(),array_search(),array_key_exists().

The following introduces the definitions and functions of these three PHP array functions.

1, PHP array search function in_array(value,array,type)
The function of this function is to search for the specified value value in the array, type is an optional parameter, If this parameter is set to true, it is checked whether the type of the searched data and the value of the array are the same, that is, they are equal to each other.

<?php
$people = array("Peter", "Joe", "Glenn", "Cleveland");
if(in_array("Glenn",$people)){
  echo "Match found";
}else{
  echo "Match not found";
}
?>

Output:
Match found

Second, PHP array search function array_key_exists(key,array)
This function is to determine whether the specified key exists in an array array. Returns true if the key exists, false otherwise.

<?php
$a=array("a"=>"Dog","b"=>"Cat");
if(array_key_exists("a",$a)){
 echo "Key exists!";
}else{
 echo "Key does not exist!";
}
?>

Output:
Key exists!

Three, php array search function array_search(value,array,strict)
array_search() function is the same as in_array(), in the array Find a key value in . If the value is found, the key corresponding to the matching element is returned. If not found, returns false. Note that prior to PHP 4.2.0, functions returned null instead of false on failure. Similarly, if the third parameter strict is specified as true, the key name of the corresponding element will only be returned if the data type and value are consistent.

<?php
$a=array("a"=>"Dog","b"=>"Cat","c"=>5,"d"=>"5");
echo array_search("Dog",$a);
echo array_search("5",$a);
?>

Output:
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After actual performance comparison, when the amount of data is not large, such as less than 1000, any search method can be used, and it will not be a performance problem. bottleneck.
But when the amount of data is relatively large, it is more appropriate to use array_key_exists.
According to tests, array_key_exist is more than ten or even dozens of times more efficient than in_array.

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!

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