Php array search (multi-dimensional array search)

There are many ways to implement array search in php. I know that the simplest thing is to compare in_array with the array traversal. there are more and better methods. I will introduce them below. One-dimensional data

There are many ways to implement array search in php. I know that the simplest thing is to compare in_array with the array traversal. there are more and better methods. I will introduce them below.

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 area is case sensitive. the code is as follows:

2. $ People = array ("Peter", "Joe", "Glenn", "Cleveland ");
3. If (in_array ("Glenn", $ people ))
4. {
5. Echo "Match found ";
6. }
7. Else
8. {
9. Echo "Match not found ";
10. }
11. ?>

Output: Match found

Array_key_exists () function

If a specified key is found in an array, the array_key_exists () function returns true; otherwise, the function returns false in the following format:

Boolean array_key_exists (mixed key, array );

The following example searches for apple in the array key. if it is found, the color of the fruit is output. the code is as follows:

1. $ Fruit ["apple"] = "red ";
2. $ Fruit ["banana"] = "yellow ";
3. $ Fruit ["pear"] = "green ";
4. If (array_key_exists ("apple", $ fruit )){
5. Printf ("apple's color is % s", $ fruit ["apple"]);
6. }
7. // Apple's color is red

Array_search () function

The array_search () function searches for a specified value in an array. if it is found, the corresponding key is returned. otherwise, false is returned. the format is as follows:

Mixed array_search (mixed needle, array haystack [, boolean strict])

The following example searches for a specific date (December 7) in $ fruits. if it is found, the related information is returned. the code is as follows:

1. $ Fruits ["apple"] = "red ";
2. $ Fruits ["banana"] = "yellow ";
3. $ Fruits ["watermelon"] = "green ";
4. $ Founded = array_search ("green", $ fruits );
5. If ($ founded)
6. Printf ("% s was founded on % s.", $ founded, $ fruits [$ founded]);
7. // Watermelon was founded on green.

Array_keys () function

The array_keys () function returns an array containing all the keys found in the searched array. the format is as follows:

Array array_keys (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. the code is as follows:

1. $ Fruits ["apple"] = "red ";
2. $ Fruits ["banana"] = "yellow ";
3. $ Fruits ["watermelon"] = "green ";
4. $ Keys = array_keys ($ fruits );
5. Print_r ($ keys );
6. // Array ([0] => apple [1] => banana [2] => watermelon)

Array_values () function

The array_values () function returns all values in an array and automatically provides a numerical index for the returned array. the format is as follows:

Array array_values (array)

The following example gets the values of each element found in $ fruits. the code is as follows:

1. $ Fruits ["apple"] = "red ";
2. $ Fruits ["banana"] = "yellow ";
3. $ Fruits ["watermelon"] = "green ";
4. $ Values = array_values ($ fruits );
5. Print_r ($ values );
6. // Array ([0] => red [1] => yellow [2] => green)

All of the above is a one-dimensional array search. if you want to implement two-dimensional data or multi-dimensional data, we can refer to the following example.

Php searches for the key value of a multi-dimensional array,For example:

1. $ Foo [1] ['A'] ['XX'] = 'bar 1 ';
2. $ Foo [1] ['B'] ['XX'] = 'bar 2 ';
3. $ Foo [2] ['A'] ['BB '] = 'bar 3 ';
4. $ Foo [2] ['A'] ['yy'] = 'bar 4 ';
5. $ Foo [3] ['c'] ['DD'] = 'bar 3 ';
6. $ Foo [3] ['F'] ['GG '] = 'bar 3 ';
7. $ Foo ['info'] [1] = 'bar 5 ';

If you want to find bar 3, how can you find it? there are three results, and all three results are required. See the following function:

1. Function array_search_re ($ needle, $ haystack, $ a = 0, $ nodes_temp = array ()){
2. Global $ nodes_found;
3. $ A ++;
4. Foreach ($ haystack as $ key1 => $ value1 ){
5. $ Nodes_temp [$ a] = $ key1;
6. If (is_array ($ value1 )){
7. Array_search_re ($ needle, $ value1, $ a, $ nodes_temp );
8. }
9. Else if ($ value1 ===$ needle ){
10. $ Nodes_found [] = $ nodes_temp;
11. }
12. }
13. Return $ nodes_found;
14. }

This function returns the output key name for all the content to be searched.

1. $ Result = array_search_re ('Bar 3', $ foo );
2. Print_r ($ result );
3. // The output result is as follows:
4. Array ([0] => Array ([1] => 2 [2] => a [3] => bb)
5. [1] => Array ([1] => 3 [2] => c [3] => dd)
6. [2] => Array ([1] => 3 [2] => f [3] => gg)
7. )

Php searches for the key name of a multi-dimensional array. the code is as follows:

1. Function array_search_key ($ needle, $ haystack ){
2. Global $ nodes_found;
3. Foreach ($ haystack as $ key1 => $ value1 ){
4.  
5. If ($ key1 ===$ needle ){
6.  
7. $ Nodes_found [] = $ value1;
9. }
10. If (is_array ($ value1 )){
11. Array_search_key ($ needle, $ value1 );
12. }
15. }
16. Return $ nodes_found;
17. }
18. $ Result = array_search_key ('A', $ foo );
19. Print_r ($ result );
20. // The output result is as follows:
21. Array
22. (
23. [0] => Array
24. (
25. [Xx] => bar 1
26. )
27. [1] => Array
28. (
29. [Bb] => bar 3
30. )
31. [2] => Array
32. (
33. [Yy] => bar 4
34. )
35. )