PHP Array Search (multidimensional array search) _php tutorial

In PHP to implement the array search method There are many, I know the simplest is in_array and iterate after the array and then a comparison, there are more and better ways, let me introduce.

One-dimensional array search is simple In_array ()

If the value parameter is a string and the type parameter is set to True, the search is case-sensitive

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$people = Array ("Peter", "Joe", "Glenn", "Cleveland"); if (In_array ("Glenn", $people)) { echo "Match found"; } Else { echo "Match not Found"; } ?> Output: Match found

Array_key_exists () function

If a specified key is found in an array, the function array_key_exists () returns True, otherwise false is returned. 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, outputs 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"]); } Apple ' s color is red

Array_search () function

The Array_search () function searches for a specified value in an array, returns the corresponding key if found, otherwise returns false. 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]); Watermelon was 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 the optional parameter search_value is included, 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); 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 each element found in $fruits:

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$fruits ["apple"] = "red"; $fruits ["banana"] = "yellow"; $fruits ["Watermelon"]= "green"; $values = Array_values ($fruits); Print_r ($values); Array ([0] = red [1] = yellow [2] = = green)

The above is only one-dimensional array search, if you want to implement two-dimensional data or multidimensional data we can refer to the following examples

1 PHP searches for a multidimensional array of key values

As in the following example:

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$foo [1][' a '] [' xx '] = ' bar 1 '; $foo [1][' B '] [' xx '] = ' bar 2 '; $foo [2][' a '] [' bb '] = ' bar 3 '; $foo [2][' a '] [' yy '] = ' bar 4 '; $foo [3][' C '] [' dd '] = ' bar 3 '; $foo [3][' F '] [' gg '] = ' bar 3 '; $foo [' info '][1] = ' Bar 5 '; If you want to find bar 3 how to find it. There are three results, and these three results are all, look at the following function: --------------------------------------------------------------------------------------------------------------- ---------------- function Array_search_re ($needle, $haystack, $a =0, $nodes _temp=array ()) { Global $nodes _found; $a + +; foreach ($haystack as $key 1=> $value 1) { $nodes _temp[$a] = $key 1; if (Is_array ($value 1)) { Array_search_re ($needle, $value 1, $a, $nodes _temp); } else if ($value 1 = = = $needle) { $nodes _found[] = $nodes _temp; } } return $nodes _found; } --------------------------------------------------------------------------------------------------------------- ------------------ This function will return all the contents of the above search to the key name to $result = Array_search_re (' Bar 3 ', $foo); Print_r ($result); The output is as follows: Array ([0] = = Array ([1] = 2 [2] = a [3] = BB) [1] = = Array ([1] = 3 [2] = c [3] = dd) [2] = = Array ([1] = 3 [2] = f [3] = = GG) )

PHP searches for the key names of multidimensional arrays

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function Array_search_key ($needle, $haystack) { Global $nodes _found; foreach ($haystack as $key 1=> $value 1) { if ($key 1=== $needle) { $nodes _found[] = $value 1; } if (Is_array ($value 1)) { Array_search_key ($needle, $value 1); } } return $nodes _found; } $result = Array_search_key (' A ', $foo); Print_r ($result); The output is as follows: Array ( [0] = = Array ( [XX] = bar 1 ) [1] = = Array ( [BB] = Bar 3 ) [2] = = Array ( [YY] = Bar 4 ) )

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