php - How do I extract capitalised words from a string

Question

Take this string:

Israel agrees to significant easing of Gaza blockade

I want to return the capitalised words, separated by a comma, like this:

Israel,Gaza

I imagine it must be possible. Any ideas?

Answer 1

Split the string into it's words with explode(' '), iterate through the words and check if the word is capitalized by checking if it's first letter ($str[0]) is the same as its uppercase variant (strtoupper($str[0])). You can fill an array with the results and then join(',') it