How to Make a String Lowercase or Uppercase in PHP

John on September 04, 2020

Sometimes all characters in a string need to be changed from uppercase to lowercase and visa versa. Fortunately, PHP has built-in functions for changing the case of characters in both directions.

To Lowercase Using strtolower()

To convert a string to lower case in PHP use the strtolower() function. Pass the string to lowercase inside the () (parenthesis) - this can be a variable or the string itself.

strtolower("mIxEd CASE TeXt.");

mixed case text.

To Uppercase Using strtoupper()

To convert every character of a string to uppercase use the strtoupper() function. It accepts one parameter, the string/variable to uppercase.

strtoupper("mIxEd CASE TeXt.");

MIXED CASE TEXT.

Conclusion

You now know how to change the case of every character in a string to uppercase or lowercase using PHP.