try_again = true;
while try_again
transactionType= input('1:withdraw 2:deposit 3:account balance 4:end use');
switch transactionType
case 1
if it works out
try_again = false;
end
So when you detect specifically that you are done then set the exit flag.
There is another way:
while true
transactionType= input('1:withdraw 2:deposit 3:account balance 4:end use');
switch transactionType
case 1
if everything works out
break;
end
do not break if you need to try again
Note that you would typically have an indefinite loop anyhow, to allow multiple transactions, continuing until the user ends (or a sanity check is reached)
