C++ Programmer Question:
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Explain me what will i and j equal after the code below is executed? Explain your answer.
int i = 5;
int j = i++;?
Answer:
After the above code executes, i will equal 6, but j will equal 5.
Understanding the reason for this is fundamental to understanding how the unary increment (++) and decrement (--) operators work in C++.
When these operators precede a variable, the value of the variable is modified first and then the modified value is used. For example, if we modified the above code snippet to instead say int j = ++i;, i would be incremented to 6 and then j would be set to that modified value, so both would end up being equal to 6.
However, when these operators follow a variable, the unmodified value of the variable is used and then it is incremented or decremented. That’s why, in the statement int j = i++; in the above code snippet, j is first set to the unmodified value of i (i.e., 5) and then i is incremented to 6.
Understanding the reason for this is fundamental to understanding how the unary increment (++) and decrement (--) operators work in C++.
When these operators precede a variable, the value of the variable is modified first and then the modified value is used. For example, if we modified the above code snippet to instead say int j = ++i;, i would be incremented to 6 and then j would be set to that modified value, so both would end up being equal to 6.
However, when these operators follow a variable, the unmodified value of the variable is used and then it is incremented or decremented. That’s why, in the statement int j = i++; in the above code snippet, j is first set to the unmodified value of i (i.e., 5) and then i is incremented to 6.
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