C language prefix and postfix increment or decrement operators

1. Prefix increment/decrement (++a / --a)

• When using prepending increment or decrement, the variable is first incremented or decremented by 1, and then the new value is returned.

int a = 5;

int b = ++a; 

// 先将a加1变为6，然后将6赋给b，所以之后a为6，b也为6。

2. Postincrement/decrement (a++) / (a- -)

• The operation of the post-fixed version is to return the current value of the variable first, and then increase or decrease it by 1.

int a = 5;

int b = a++; 

// 先将a的当前值5赋给b，然后将a加1变为6，所以之后a为6，b仍为5。