Will adding php arrays merge duplicate values?

php array addition will not merge duplicate values. In PHP, you can use the " " operator to add one or more arrays. These arrays will be merged to return a new array. The syntax is "array 1 array 2..". The elements of the subsequent arrays will be appended to the end of the first element. , it has no effect whether the value is repeated; but if the key name is repeated, the previous element will overwrite the following element.

The operating environment of this tutorial: windows7 system, PHP version 8.1, DELL G3 computer

php array addition will not be merged Duplicate value.

In PHP, you can use the " " operator to add one or more arrays, and these arrays will be merged to return a new array; syntax:

数组1+数组2+...

The following array The element will be appended to the end of the first element

1,"a2"=>2,"a3"=>3,"a4"=>4,"a5"=>5); $arr2=array("b1"=>6,"b2"=>5,"b3"=>4,"b4"=>3,"b5"=>2,"b6"=>1); var_dump($arr1); var_dump($arr2); $arr=$arr1+$arr2; var_dump($arr); ?>

It can be seen that whether the value is repeated has no effect, and duplicate values will not be merged.

But repeated key names will have an impact. If the key names are repeated, the previous elements will overwrite the following elements

 "apple", "b" => "banana"); $arr2 = array("a" => "pear", "b" => "strawberry", "c" => "cherry"); var_dump($arr1); var_dump($arr2); $arr=$arr1+$arr2; var_dump($arr); ?>

Recommended study: "PHP video tutorial》

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