The method of searching and search array elements in PHP summarize _php skills

This article illustrates the method of finding and searching array elements in PHP. Share to everyone for your reference. The specific analysis is as follows:

Finding, filtering, and searching array elements are some of the common features of array operations. Here are a few related functions.

In_array () function

The In_array () function searches for a specific value in an array rollup and returns False if the value is found to return true. The form is as follows:

Boolean In_array (mixed Needle,array Haystack[,boolean strict]);

Look at the example below to find out whether the variable Apple is already in the array, and if it is, output a piece of information:

$fruit = "Apple";
$fruits = Array ("Apple", "banana", "orange", "pear");
if (In_array ($fruit, $fruits)) 
 echo "$fruit already in array";

The third argument is optional, which forces In_array () to consider the type when searching.

Array_key_exists () function

If a specified key is found in an array, the function array_key_exists () returns TRUE, otherwise it returns false. The form is as follows:

Boolean array_key_exists (mixed Key,array array);

The following example searches for Apple in the array key and, if found, prints the color of the fruit:

$fruit ["apple"] = "red";
$fruit ["banana"] = "yellow";
$fruit ["pear"] = "green";
if (array_key_exists ("Apple", $fruit)) {
 printf ("Apple's color is%s", $fruit ["Apple"]);
}

Execute this code to get the result:

Copy Code code as follows:

Apple ' s color is red

Array_search () function

The Array_search () function searches an array for a specified value and returns False if it finds the corresponding key. The form is as follows:

Mixed Array_search (mixed Needle,array Haystack[,boolean Strict])

The following example searches for a specific date in $fruits (December 7) and, if found, returns information about the corresponding state:

$fruits ["apple"] = "red";
$fruits ["banana"] = "yellow";
$fruits ["Watermelon"]= "green";
$founded = Array_search ("green", $fruits);
if ($founded) 
 printf ("%s is founded on%s.", $founded, $fruits [$founded])

The results of the program operation are as follows:

Copy Code code as follows:

Watermelon is founded on green.

Array_keys () function

The Array_keys () function returns an array that contains all the keys found in the searched array. The form is as follows:

Array Array_keys (array array[,mixed search_value])

If you include an optional parameter search_value, only the key that matches the value is returned. The following example outputs all the arrays found in the $fruit array:

$fruits ["apple"] = "red";
$fruits ["banana"] = "yellow";
$fruits ["Watermelon"]= "green";
$keys = Array_keys ($fruits);
Print_r ($keys);

The results of the program operation are as follows:

Copy Code code as follows:

Array ([0] => Apple [1] => banana [2] => watermelon)

Array_values () function

The Array_values () function returns all the values in an array and automatically provides a numeric index for the returned array. The form is as follows:

Array array_values (array array)

The following example gets the values of the elements found in the $fruits:

$fruits ["apple"] = "red";
$fruits ["banana"] = "yellow";
$fruits ["Watermelon"]= "green";
$values = Array_values ($fruits);
Print_r ($values);

The results of the program operation are as follows:

Copy Code code as follows:

Array ([0] => red [1] => yellow [2] => Green)

I hope this article will help you with your PHP program design.