Unexpected short circuit evaluation when used more than one logical operators in C-CodePudding

In a C program: 1 || 0 && 0 results in 1. I thought this behavior as the OR operator has short-circuited rest of the right side (0 && 0) because of 1 on the left side. But 0 && 0 || 1 also results in 1. I am confused why 0 on the left side of AND operator has not short circuited 0 || 1 and the answer is not 0. Please guide me!

CodePudding user response：

This has to do with operator precedence.

The logical AND operator has higher precedence than the logical OR operator ||. So this:

1 || 0 && 0

Parses as:

1 || (0 && 0)

And this:

0 && 0 || 1

Parses as:

(0 && 0) || 1

So in the latter case, first 0 && 0 is evaluated. This results in the value 0, so now you have 0 || 1. The left side of the OR is false so this causes the right side to be evaluated, causing the || operator to result in 1.