The usual way to examine data in your program is with the print (p) command or its synonym inspect. It evaluates and prints the value of an expression of the language your program is written in.
A lower-level way of examining data is with the x command. It examines data in memory at a specified address and prints it in a specified format. See "Examining memory."
If you're interested in information about types, or about how the fields of a structure or class are declared, use the ptype exp command rather than print. See "Examining the symbol table."