Convert a sting to all lower case - strtolower();

the quick brown fox jumps over the lazy dog.

Convert a sting to all upper case - strtoupper();

THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG.

Convert a sting so that forst word has an initial cap -ucfirst();

The QUICK brown fox jumps over the LAZY dog.

Convert a sting to have all initial caps - ucwords();

The QUICK Brown Fox Jumps Over The LAZY Dog.

Find the number cound of characters in a string - strlen();

44

Find a string within a string - strstr();

fox jumps over the LAZY dog.

Find and replace a string pattern with a new string - str_replace();

the QUICK brown fox jumps over the LAZY cat.

Remove whitespace (extra spaces) from the beginning or end of a string. Print to screen uing pre tag to see the whitespace - trim();

Before

jdoe 

After

jdoe