1. <script><br /> varnum = 7;<br /> varstr = '我爱你~中国~'; //str.length = 7<br /> console.log(num > 5 && str.length >= num); //t t true<br /> console.log(num < 5 && str.length >= num); //f t false<br /> console.log(!(num < 10)); //!t false<br /> console.log(!(num < 10 || str.length == num)); //!(t) false<br /> </script>

    .