4 replies to this topic

[VakhoQ]

This function is like the strrev():

function F($str){

 for($i=strlen($str); $i>=0; $i--){

  echo $str[$i];

  }

}


$str="hello";

F($str);

but there are some errors on this line: echo $str[$i];
Error: Uninitialized string offset.

what mistake do i have?.. its interesting...

[VakhoQ]

that's something like this:

[webcodez]

You're starting at index = strlen($str) but that index does not exist, the highest index is strlen($str)-1. Take for example the world "hi", then index0 stands for "h" and index1 stands for "i" but strlen("hi") is 2 (but index 2 itself is out of range). So that's the mistake, you did take 0 as initial index but strlen starts counting index0 as 1, in other words: the max. index would be the string length minus 1.

function F($str){ 

 for($i=strlen($str)-1; $i>=0; $i--){ 

  echo $str[$i]; 

  } 

} 


$str="hello"; 

F($str); 

^^.

[VakhoQ]

webcodez said:

You're starting at index = strlen($str) but that index does not exist, the highest index is strlen($str)-1. Take for example the world "hi", then index0 stands for "h" and index1 stands for "i" but strlen("hi") is 2 (but index 2 itself is out of range). So that's the mistake, you did take 0 as initial index but strlen starts counting index0 as 1, in other words: the max. index would be the string length minus 1.

function F($str){ 

 for($i=strlen($str)-1; $i>=0; $i--){ 

  echo $str[$i]; 

  } 

} 


$str="hello"; 

F($str); 

^^.

Oh, You are right! thanks a lot! :)

[webcodez]

You're welcome! I'm glad I could help :).