c - 在 C 中，条件表达式的计算结果总是为 0 还是 1？

Question

&& 和|| 等条件表达式，它们的计算结果总是为 0 还是 1？或者对于 true 条件，除 1 以外的数字都是可能的？我问是因为我想分配一个这样的变量。

int a = cond1 && cond2;

我想知道我是否应该改为执行以下操作。

int a = (cond1 && cond2)? 1:0;

Answer 1

逻辑运算符(&&、|| 和 !)的计算结果都是 1 或 0。

C99 §6.5.13/3:

The && operator shall yield 1 if both of its operands compare unequal to 0; otherwise, it yields 0. The result has type int.

C99 §6.5.14/3:

The || operator shall yield 1 if either of its operands compare unequal to 0; otherwise, it yields 0. The result has type int.

C99 6.5.3.3/5:

The result of the logical negation operator ! is 0 if the value of its operand compares unequal to 0, 1 if the value of its operand compares equal to 0. The result has type int. The expression !E is equivalent to (0==E).