How to calculate a % of a number!

[rookiecoder]

Hi Guys,

I just started´my class this week and I have a simple question!

What is the code for calculating a percentage of a number? For example:

Balance: $1000
Rate: 4,2%
Result: $42

Any and all help is greatly appreciated! Thank you!

[TwilightSpectre]

Easy way: Do it like in maths. You have a number: Multiply by the percentage / 100. For example:
Balance: $1000
Rate: 4.2%

Result = 1000 * (4.2 / 100) = 42

Now you can put it in code (I'm assuming this is homework)

[Codermik]

value / 100 * percentage = 4.2% of value

[rookiecoder]

That easy huh! Thank you guys! =)

[rookiecoder]

OK here it goes....
So I made an attempt to write this in code and it did not work! The ruselt came to: 0 when ´running the program!

Balance: $1000
Rate: 4,2%
Result: $42

     cout << "Enter deposit amount!";
    int deposit;
    cin >> deposit;
    int rate;
    cout << "Enter your rate!";
    cin >> rate;

    int result = deposit * (rate/100);
    cout << result

[MikeyBoy]

The problem is that you're using integer arithmetic. (rate/100) is being rounded down to 0.

You need to use floating-point types, not integers.

Oh, and you end a code block with [/code], not [code]. It's easier if you use the buttons to the right of the editor :)

[rookiecoder]

Yes sorry about the [/code]...

I changed int to float and it worked perfect!

Thanks again all!!

[MikeyBoy]

You're welcome! Glad it worked :)