Thread: Need help with making code more efficent! - PLEASE HELP:(

So basically, I am developing a program to calculate Annual and Monthly premiums for Insurance.

I am a beginners level Java Programmer. Studying Computer Science. and here is my code.

 public double calculatePremium(double premium, int time, int mostExpensive, int noGadgets) {
 
         if (time == 2) { // when user hits 2 this calcualtes monthly premium
            if (noGadgets == 1 && noGadgets  <= 500) {
                premium = 4.99;
            }
            if (noGadgets  == 1 && noGadgets  > 500 && mostExpensive <= 750) {
                premium = 6.15;
            }
 
            if (noGadgets  == 1 && noGadgets  > 750 && mostExpensive <= 1000) {
                premium = 7.50;
            }
 
 
            if (noGadgets  >= 2 && noGadgets  <= 3 && mostExpensive <= 500) {
                premium = 17.30;
            }
            if (noGadgets  >= 2 && noGadgets  <= 3 && mostExpensive > 500 &&mostExpensive <= 750) {
                premium = 6.15;
            }
 
            if (noGadgets  >= 2 && noGadgets  <= 3 && mostExpensive > 750 && mostExpensive <= 1000) {
                premium = 7.50;
            }
 
 
            if (noGadgets  >= 4 && noGadgets <= 5 && mostExpensive <= 500) {
                premium = 14.99;
            }
            if ((noGadgets  >= 4 && noGadgets  <= 5) && mostExpensive > 500 && mostExpensive<= 750) {
                premium = 18.60;
            }
 
            if (noGadgets  >= 4 && noGadgets  <= 5 && mostExpensive> 750 && mostExpensive <= 1000) {
                premium = 21.82;
            }
 
 
            return premium;
 
 
 
        }
 
 
 
        if (time == 1) { // if user hits 1 on kbd then calculate annual premium
            if (noGadgets  == 1 && noGadgets  <= 500) {
                premium = 4.99 * 12.00;
            }
            if (noGadgets  == 1 && noGadgets  > 500 && mostExpensive <= 750) {
                premium = 6.15 * 12.00;
            }
 
            if (noGadgets  == 1 && noGadgets  > 750 && mostExpensive <= 1000) {
                premium = 7.50 * 12.00;
            }
 
 
            if (noGadgets >= 2 && noGadgets  <= 3 && mostExpensive <= 500) {
                premium = 17.30 * 12.00;
            }
            if (noGadgets  >= 2 && noGadgets  <= 3 && mostExpensive > 500 && mostExpensive <= 750) {
                premium = 6.15 * 12.00;
            }
 
            if (noGadgets  >= 2 && noGadgets  <= 3 && mostExpensive > 750 && mostExpensive <= 1000) {
                premium = 7.50 * 12.00;
            }
 
 
            if (noGadgets  >= 4 && noGadgets  <= 5 && mostExpensive <= 500) {
                premium = 14.99 * 12.00;
            }
            if ((noGadgets  >= 4 && noGadgets  <= 5) && mostExpensive > 500 && mostExpensive <= 750) {
                premium = 18.60 * 12.00;
            }
 
            if (noGadgets  >= 4 && noGadgets  <= 5 && mostExpensive > 750 && mostExpensive <= 1000) {
                premium = 21.82 * 12.00;
            }
 
 
            return premium;
 
 
 
        }
        return premium;
    }

My lecturers advise me not to use too many IF statements, but I'm really unsure on how to get around this?
The code above is using LOADS of IF statements, and I need to make it more efficient. Could I use a loop? and if so, then how?

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Many of the if statements make no sense. For example:

if (noGadgets == 1 && noGadgets > 500

If noGadgets is 1 it won't be greater than 500

if (noGadgets == 1 && noGadgets <= 500) {
premium = 4.99;
}


If it is equal to 1, it will always be less than or equal to 500.

if (noGadgets == 1 && noGadgets > 500 && mostExpensive <= 750) {
premium = 6.15;
}

This can never be true as it cannot be both equal to one and greater than 500 at the same time.

Why are you passing it the variable "premium" if all you do is change it in the method? Why not just have a variable inside the method called "premium" instead?


You can use if, else if, else to avoid using too many if statements.

You can have an if structure like this


if (statement)


also, this is allowed.

if (condition)
statement;

else
statement;


Also, you can do this

if (condition)
statement;

else if (condition)
statement;
..... (can have more else ifs if needed)

else
statement;

Note: Unless you have brackets after a condition with an if, else if, or else statement, it will only apply to the statement right after the condition.

Google if, else if, else for more info.