how to add a float array to a float vector in c++

Question

here is the problem. I have a float vector called vec:

std::vector<float> vec {1.1,2.2};

Now there is also a float array called, arr:

float arr[]={3.3 4.4 5.5};

So the question is how to add the array to the vector such that at the end we get {1.1 2.2 3.3 4.4 5.5} a longer float vector.

I tried this,

vec.insert(vec.begin(), arr,arr+3);

But the compiler gives a long error starting with

"error: no match in operator + in arr+3"

sbarzowski · Accepted Answer · 2015-02-28 20:03:24Z

3

Something like that works for me:

std::vector<float> vec {1.1, 2.2};
float arr[] = {3.3, 4.4, 5.5};
vec.insert(vec.end(), arr, arr+3);

I guess you made some simple mistakes like:

You forgot to separate values in your float array by commas. In the question they are separated only by spaces and in effect arr is not successfully declared and you get your error.
If you want to add your values at the end, you have to vec.insert(vec.end(),...). The first argument is the iterator before which your range will be inserted.

answered Feb 28, 2015 at 20:03

sbarzowski

3,1212 gold badges23 silver badges26 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

thanks. What if arr is also a vector? like this std::vector <float> arr

Then instead of arr, arr + 3 you need arr.begin(), arr.end(). And of course declaration and initialization looks like of vec.