Question

c = (a -= a - 5), (a = b, b + 3);和c =（ (a -= a - 5), (a = b, b + 3)）;区别？

若有以下程序段，其输出结果是 int a= 0, b = 0, c = 0;
c = (a-=a-5), (a=b,b+3);
printf("%d,%d,%d\n",a,b,c);
把c = (a -= a - 5), (a = b, b + 3);换成c =（ (a -= a - 5), (a = b, b + 3)）;

Answer 1

c = (a -= a - 5), (a = b, b + 3);即 ( c = (a -= a - 5) ) , (a = b, b + 3); abc最后依次为0,0,5

c =（ (a -= a - 5), (a = b, b + 3)）; abc最后依次为0,0,3

差别是由于逗号运算符优先级最低,表达式整体是逗号表达式还是赋值表达式,影响了最终变量c的值