PHP combined with 2 numeric key array values Program _php tutorial

PHP Merge 2 numeric key array values of the program

In PHP, the array_merge is the most reliable function, the following we use the Array_merge function when merging is mainly for the two array of key values for the processing of numbers.

To understand a basic point of knowledge first

The combination of two arrays in PHP can use + or array_merge, but there is still a difference between them, and these differences if you do not know clearly the project will be fatal!

The main difference is that if the same key name appears in two or more arrays, the key name is a string or a number, you need to be aware

1) When the key name is a number, the value after Array_merge () will not overwrite the original value, but append it to the back, but the + merge array will return the first occurrence as the final result, and the values of the following array with the same key name "Discard" (not overwrite)

2) When the key name is a string, Array_merge () overwrites the previous value of the same key name, but + still returns the first occurrence as the final result, and "discards" the values of the following array with the same key name (not overwrite).

The code is as follows

$a = Array (' A ', ' B '); $b = Array (' C ', ' d '); $c = $a + $b; Var_dump ($a); Var_dump (Array_merge ($a, $b)); Output: array 0 = String ' a ' (length=1) 1 = String ' B ' (length=1) Array 0 = String ' a ' (length=1) 1 = string ' B ' (length=1) 2 = String ' C ' (length=1) 3 = String ' d ' (length=1) ++++++++++++++++++++++++++++++++++++++++++ $a = Array ( 0 = ' a ', 1 = ' B ' ); $b = Array ( 0 = ' C ', 1 = ' B ' ); $c = $a + $b; Var_dump ($c); Var_dump (Array_merge ($a, $b)); Output: array 0 = String ' a ' (length=1) 1 = String ' B ' (length=1) Array 0 = String ' a ' (length=1) 1 = string ' B ' (length=1) 2 = String ' C ' (length=1) 3 = String ' B ' (length=1) ++++++++++++++++++++++++++++++++++++++++++ $a = Array (' A ', ' B '); $b = Array ( ' 0 ' = ' C ', 1 = ' B ' ); $c = $a + $b; Var_dump ($c); Var_dump (Array_merge ($a, $b)); //output: array 0 = String ' a ' (length=1) 1 = String ' B ' (length=1) Array 0 = String ' a ' (length=1) 1 = string ' B ' (length=1) 2 = String ' C ' (length=1) 3 = String ' B ' (length=1) ++++++++++++++++++++++++++++++++++++++++++ $a = Array ( 0 = ' a ', 1 = ' B ' ); $b = Array ( ' 0 ' = ' C ', ' 1 ' = ' B ' ); $c = $a + $b; Var_dump ($c); Var_dump (Array_merge ($a, $b)); Output: array 0 = String ' a ' (length=1) 1 = String ' B ' (length=1) Array 0 = String ' a ' (length=1) 1 = string ' B ' (length=1) 2 = String ' C ' (length=1) 3 = String ' B ' (length=1)

All right, so much for this, let's take a look at the value of merging 2 numeric key arrays

The code is as follows

/** * PHP combined 2 numeric key array values * * @param array $arr 1 * @param array $arr 2 * @return Array * @author www.111cn.net */ function New_array_merge ($arr 1, $arr 2) { $arr = Array_flip ($arr 1) + Array_flip ($arr 2); Return Array_keys ($arr); } $arr 1 = array (' AA ', ' BB ', ' cc '); $arr 2 = Array (' Aa2 ', ' BB ', ' cc2 '); $arr = New_array_merge ($arr 1, $arr 2); Print_r ($arr); Output: Array ( [0] = = AA [1] = BB [2] + = CC [3] = Aa2 [4] = CC2 )

http://www.bkjia.com/PHPjc/917546.html www.bkjia.com true http://www.bkjia.com/PHPjc/917546.html techarticle PHP Merge 2 numeric key array of values of the program PHP array merge Array_merge is the most reliable function, the following we in the use of Array_merge function merging is mainly for two arrays of keys ...

