Percentage income problem

Hi Stephen,

Just picked up your question on a quiet Sunday evening. I wrote a small program for a simple GUI based tax calculator Complete project on Github

Sharing below an excerpt from the main project that lays down the logic

// Checking condition for 1st 300000 of taxable income at 7% 
        if(totalIncome <= 300000){
            taxValue = totalIncome * 0.07;
        } 
        else if (totalIncome > 300000){
            taxValue = 300000 * 0.07;
        }

        totalIncome = totalIncome - 300000;


        // Checking condition for next 300000 of taxable income at 11% 
        if(totalIncome == 0 || totalIncome < 0){
            return taxValue;
        }
        else if (totalIncome<300000 && !(totalIncome < 0)){
            taxValue = taxValue + (totalIncome * 0.11);
        } 
        else if (totalIncome > 300000){
            taxValue = taxValue + (300000*0.11);
        }

        totalIncome = totalIncome - 300000;

        // ... and so on for other conditions

So basically this is what the algorithm looks like

1) Input total income

2) Set total tax value to 0

3) Check first condition

3.1) If total income is less than or equal to 300000 then tax value is equal to 7% of given income. Return the tax result
3.2) Else if income is greater than 300000 then tax value is equal to 7% of 300000. Return the tax result
3.3) Subtract 300000 from the total income

4) Check next condition

4.1) If total income is equal to zero or a negative value return the perviously calculated tax result

4.2) Else if total income after deduction in 3.3 is less than 300000 and not a negative value then tax value is equal to tax value calculated in 3.2 + 11% of remaining income. Return the tax result

4.3) Else if income is greater than 300000 then tax value is equal to tax value calculated in 3.2 + 11% of 300000 . Return tax value result

4.4) Subtract 300000 again from the total income

5) Repeat steps above for other conditions

Again this is a casual attempt and there could be other easier ways to do this though I'm always open for suggestions.

Hope this helps.