如何将长字分割成字？

Question

I have a long word, for example:

welcometostackoverflow

or

betweenparagraphs

How to get string or array like this in PHP?

Welcome to Stack Overflow

or

between paragraphs

Sample results: http://www.bing.com/images/search?q=betweenparagraphs&go=&qs=n&sk=&form=QBIR

Answer 1

It's pretty much impossible since your code cannot know where a word ends. Even with a dictionary there would be ambiguous situations.

Answer 2

Simply.. You can't do that not even with large collection of sample words in an array or a file or something else.

Reasons are:

1. Your input string as i thought will not be welcometostackoverflow everytime.

2. It will cause ambiguous situation in large no. of cases.

   for example : overflow : it may be over or flow or overflow or low ..