en.javascript.info/1-js/02-first-steps/11-logical-ops/8-if-question/solution.md
Ilya Kantor 9ad9063d00 up
2016-11-28 21:35:42 +03:00

415 B

The answer: the first and the third will execute.

Details:

// Runs.
// The result of -1 || 0 = -1, truthy
if (-1 || 0) alert( 'first' );

// Doesn't run
// -1 && 0 = 0, falsy
if (-1 && 0) alert( 'second' );

// Executes
// Operator && has a higher precedence than ||
// so -1 && 1 executes first, giving us the chain:
// null || -1 && 1  ->  null || 1  ->  1
if (null || -1 && 1) alert( 'third' );