A summary of the methods of finding and searching array elements in PHP

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:

 

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$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:

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$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:

The

code is 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:

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$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:

The

code is 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:

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$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:

The code is 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:

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$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:

The

code is as follows: Array ([0] => red [1] => yellow [2] => Green)