Adding an array using a For loop

This is a discussion on Adding an array using a For loop within the C++ Programming forums, part of the General Programming Boards category; I need to add the elements of an array together using a for loop and then print the result. I ...

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    Adding an array using a For loop

    I need to add the elements of an array together using a for loop and then print the result. I know it is a simple code but I am struggling with it. Can anyone offer any advice on this?

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    C++ Witch laserlight's Avatar
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    What have you tried?
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
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    For Loop Example:
    Code:
    for(int i = 0; i < ARRAY_SIZE; i++){
    }
    Woop?

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    I'm kinda stuck at the starting point (I'm just learning this stuff). I know the basic code structure but I am struggling with the body of it. The basic structure of the for loop does help. For instance, say you had to add together 1,2,3 and 4 using a for loop. What would that look like?

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    C++ Witch laserlight's Avatar
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    Well, suppose you have two variables, sum and x. To add x to sum, you would write:
    Code:
    sum += x;
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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    So for multiple variables, say x, y, z, it would be like this?: x+=y+=z;

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    C++ Witch laserlight's Avatar
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    Nope, unless you intend to add z to y as well. In this case you are summing the elements of an array, one at a time.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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    Oh ok. So it would be: sum += x ; Where x is just the name of the array?

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    C++ Witch laserlight's Avatar
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    No, where x is the current element of the array, i.e., you would replace x with say, y[i], where y is the array name and i is the array index.
    Quote Originally Posted by Bjarne Stroustrup (2000-10-14)
    I get maybe two dozen requests for help with some sort of programming or design problem every day. Most have more sense than to send me hundreds of lines of code. If they do, I ask them to find the smallest example that exhibits the problem and send me that. Mostly, they then find the error themselves. "Finding the smallest program that demonstrates the error" is a powerful debugging tool.
    Look up a C++ Reference and learn How To Ask Questions The Smart Way

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    Elkvis- I appreciate it but Googling it is what led me this forum in the first place

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    You could need to declare a variable to hold the sum , ie. int sum=0;

    Then use a for loop to go through the elements of the array, and add it to sum.

    As such,

    Code:
    for(int i=0; i < array_size; i++)
         sum=sum + myarray[i]; //or sum += myarray[i]
    
    cout << sum;
    All this is doing is accessing the element of the array, and adding it to the value in sum, so you get the total of the array.
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