苦笔的博客

在函数中使用thisfunction foo(c, d) { return this.a + this.b + c + d}global.a = 3global.b = 4// foo执行时，this没有明确的指向，默认指向全局对象global// nodejs中是global，browser中是windowfoo(3, 4) // 14...

浏览器全局环境（global context）this === window // true

定义A closure is the combination of a function and the lexical environment within which that function was declared.This environment consists of any local variables that were in-scope at the time ...

1 定义// 4种定义方式new Date().toLocaleString(); // 2018-1-10 20:32:12// new Date(milliseconds),3年约等于11次方毫秒new Date(0).toLocaleString(); // 1970-1-1 08:00:00,不知道这是个什么日子new Date(1515

Number.MAX_VALUENumber.MIN_VALUENumber.MAX_SAFE_INTEGERNumber.MIN_SAFE_INTEGERNumber.EPSILONES采用Binary640.1 + 0.2 =