在javascript中，哪种情况会令下面表达式成立？

Question

最近读书的时候发现有时javascript会有一些匪夷所思的属性 比如：

1.1 a !== a

    console.log(NaN === NaN)

1.2 a == b && b != a

    //在IE678中显示flase(其他现代浏览器中显示false)
    console.log(document == window);
    //在IE678中显示true(其他现代浏览器中显示false)
    console.log(window == document);

1.3 a == !a

1.4 a === a+100

1.5

    console.log(3>2>1); //输出false
    console.log(1<2<3); //输出true

求 1.3 和 1.4的例子

Answer 1

var a = '0';
a == !a; //true

var a = Infinity;
a === a + 100; //true

Answer 2

var a = "0"
console.log(a==!a)

Answer 3

a = Infinity
a === a + 100

Answer 4

var a = []
a == !a