Array merge issues

$act _arr = Array (0=> ' AAA ',2=> ' BBB ');
I'm going to turn into the following string
' AAA ', ' BBB '
Use implode (', ', $act _arr);
The result is aaa,bbb.
How to use the fast method, it is best not to traverse, to achieve the effect I want.

Reply to discussion (solution)

To get single quotes, you should use escape characters!

echo "'". Implode (', ', $act _arr). "'";

That's right.
echo "'". Implode ("', '", $act _arr). "'";

Also to a

$act _arr = Array (0=> ' AAA ',2=> ' BBB '), $act _arr=array_map (' foo ', $act _arr), function foo ($v) {     return "' $v '";} echo implode (', ', $act _arr);

$str = "'". Implode ("', '", $act _arr). "'";

Understand, is to separate the comma (,), instead of ', ' separated on it can be

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