Why is the result of php array array ("a") + array ("b") still array ("a")

This article introduces the "php array array (" a ") + array (" b ") why the result is still array (" a ") related knowledge, in the actual case operation process, many people will encounter such a dilemma, then let the editor lead you to learn how to deal with these situations! I hope you can read it carefully and be able to achieve something!

I saw a question on the Internet:

The result of array ("a") + array ("b") is _ _

A.array ("a", "b")

B.array ("b", "a")

C.array ("b")

D.array ("a")

Answer: d

When the two arrays of php are added together, why does the result remain the same?

Because they are equivalent to array ("0" = > "a") + array ("0" = > "b"), they have the same key name, and the former cannot be overwritten by the latter. If it is array ("0" = > "a") + array ("0" = > "b", "1" = > "c"), then the result is equal to array ("0" = > "a", "1" = > "c").

What happens if you have the same key name in the same array?

Take a look at the code in the official php manual:

The copy code is as follows:

$switching = array (10, / / key = 0

5 = > 6

3 = > 7

'a'= > 4

11, / / key = 6 (maximum of integer-indices was 5)

'8' = > 2, / / key = 8 (integer!)

'02' = > 77, / / key =' 02'

0 = > 12 / / the value 10 will be overwritten by 12

);

It can be seen that if there is the same key name in the same array, the value of the previous key name will be overwritten (overwritten).

"php array array (" a ") + array (" b ") why the result is still array (" a ") is introduced here, thank you for reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!