simple Interest

setup Form

btnCalculate

int principal = 1000; //invest $1000
double rate = 0.05; //at 5% per annum
int time = 2; //for 2 years
        
double final_amount;
final_amount = principal + simpleInterest(principal, rate, time);
lblResult.setText(String.valueOf(final_amount));

create Sub-procedure

• use sub-procedures / sub-methods to keep your programs modular. Put your sub-procedure for simpleInterest before your calculate event procedure btnCalculateActionPerformed (or whatever you called it) as shown:


public double simpleInterest(int P, double R, int T){
	double interest = P * R * T;
	return interest;
}

challenge

• add a clear button, and add another sub-procedure, this time sub-procedure returns no value (nothing) which is what 'void' means:

public void clear(){
	lblResult.setText("");
}

• call the clear() sub-procedure from your new 'clear' button event handler