Two AND Operators

An expression with two && operators works like you expect. But let us look at the situation in detail. When the && operator is used twice in an expression, group the first && and its operands together like this:

  (4 < 8 ) && (12 <= 40 )  && (50 > 1)

is equivalent to:

( (4 < 8 ) && (12 <= 40 )) && (50 > 1)

Evaluate that first group. The result is true or false. Now use that value with the next && operator:

(          true          ) && (50 > 1)

(          true          ) && true 

                         true

The effect of this is that for the entire expression to be true, every operand must be true.

Short-circuit evaluation is still going on, so the first false value stops evaluation and causes the entire expression to be false.