Arduino and ESP32

Find the ordinal number of the character position in the string Arduino or ESP32 (indexOf)

Remove spaces in a line. Arduino or ESP32 (trim)

toUpperCase and toLowerCase Arduino or ESP32

Changing the markers in the row. Arduino or ESP32 (printf)

Select N characters in a string. Arduino or ESP32 (substring)

Replace a character in a string. Arduino or ESP32 (replace)