How to convert string to integer in microsoft access (vb) also how to use the trim function?

how to convert string to integer in microsoft access (vb) im planning to make a calculator one more thing how to use the trim function?How to convert string to integer in microsoft access (vb) also how to use the trim function?
string to integer conversion: cint(expression)

a% = cint('; 55';)

results in a% equal to 55.



a$ = trim(string/string variable)

a$ = trim('; this is a string ';)

results in a$ equal to ';this is a string';