summation using while loop until I get a certain value

hello,I am asked to sum the elements of an array until I get a certain value. I used the while loop but when I run the code it says that index exceeds matrix dimensions. Here is my code,

A=[3 4 10 3 9 10 12 4 11 9 11 10];
sum=0;
k=1:length(A);
while sum<43
    sum=sum+A(k);
    k=k+1;
end
disp(sum);
disp(k);

what could be the problem with this code? thanks...

[Stephen23]

Note that you should not call your variable sum, as this is the name of the inbuilt and very important function sum. When you define a variable/function named sum, it shadows the inbuilt function and stops it from working. This will break a lot of code!

Answer 1

[Stephen23]

This is much easier without any loops:

>> N = 43;
>> A = [3,4,10,3,9,10,12,4,11,9,11,10];
>> B = cumsum(A);
>> C = B(B<N);
>> C(end)
ans =
    39

Answer 2

[Andrei Bobrov]

A=[3 4 10 3 9 10 12 4 11 9 11 10];
sum1=0;
k=1;
while sum1<43
    sum1=sum1+A(k);
    k=k+1;
end
disp(sum1);
disp(k);

[dilara ozbay]

k=k+1 must be above the sum1 equation.. thanks:)

[Andrei Bobrov]

A=[3 4 10 3 9 10 12 4 11 9 11 10];
sum1=0;
k=1;
s = [];
while sum1 < 43
   s =sum1;
   sum1=sum1+A(k);
   k=k+1;
end
disp(s);
disp(k-1);