difference between --a and a-- c++

--a

The expression --a is a pre-decrement operator in C++. It decrements the value of variable a by 1 before using the updated value in the expression. Here is the step-by-step explanation of --a:

1. The value of a is decremented by 1.
2. The updated value of a is used in the expression where --a is present.

a--

The expression a-- is a post-decrement operator in C++. It decrements the value of variable a by 1 after using the original value in the expression. Here is the step-by-step explanation of a--:

1. The original value of a is used in the expression where a-- is present.
2. The value of a is decremented by 1 after the expression is evaluated.

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