Driver function
$ str = " abcasdsabcae " ; if ( function_1 ( $ str ) ) echo " Yes , ▁ both ▁ halves ▁ differ " . " ▁ by ▁ at ▁ least ▁ one ▁ character " ; else echo " No , ▁ both ▁ halves ▁ do ▁ " . " not ▁ differ ▁ at ▁ all " ; return 0 ; ? >