大家来看看，对于这个的理解。1.2 == true ， 大家说是false还是true？ 为什么会这样呢？
大家对于这里的理解是啥？
1.2 == true 是false
11 回复
ECMA-262 7.2.12 Abstract Equality Comparison(==) 为了方便copy过来
7.2.12 Abstract Equality Comparison
The comparison x == y, where x and y are values, produces true or false. Such a comparison is performed as follows:
1. ReturnIfAbrupt(x).
2. ReturnIfAbrupt(y).
3. If Type(x) is the same as Type(y), then
Return the result of performing Strict Equality Comparison x === y.
4. If x is null and y is undefined, return true.
5. If x is undefined and y is null, return true.
6. If Type(x) is Number and Type(y) is String,
return the result of the comparison x == ToNumber(y).
7. If Type(x) is String and Type(y) is Number,
return the result of the comparison ToNumber(x) == y.
8. If Type(x) is Boolean, return the result of the comparison ToNumber(x) == y.
9. If Type(y) is Boolean, return the result of the comparison x == ToNumber(y).
10. If Type(x) is either String, Number, or Symbol and Type(y) is Object, then
return the result of the comparison x == ToPrimitive(y).
11. If Type(x) is Object and Type(y) is either String, Number, or Symbol, then
return the result of the comparison ToPrimitive(x) == y.
12. Return false.
'1.2' == true符合第9条，返回'1.2' == ToNumber(true)，即'1.2' == 1
符合第7条，返回ToNumber('1.2') == 1，即1.2 == 1
符合第3条，返回1.2 === 1
后面就是===严格相等了，不赘述了，下面是链接
ECMA-262 7.2.13 Strict Equality Comparison(===)
@21614306 这个是因为{}对象字面量这个在浏览器中会被解析为代码块而不是对象，浏览器会尝试执行代码块，而上面并没有代码执行所以第一个只返回了9, 对于第二个，[]的Primitive的值会调用toString方式转换为空字符串,然后空字符串和9相加就是字符串"9"了，如果代码如下:
var a = {};
a + 9 => [object Object]9
