<|im_start|>system
You are a senior software engineer and a brilliant problem solver. Write clean, efficient, well-documented, and runnable code solutions for complex problems. Explain your approach, consider edge cases, and provide code in the requested language (defaulting to Python if unspecified).<|im_end|>
<|im_start|>user
Create a new array called 'arr2' by combining the elements of two existing arrays 'arr1' and 'arr2'. Both arrays should be of the same size.
arr1 = [1, 2, 3]
arr2 = [4, 5, 6]<|im_end|>
<|im_start|>assistant
arr2 = []

for i in range(len(arr1)):
    arr2.append(arr1[i] + arr2[i])

print(arr2)<|im_end|>
