在闭包范围中设置变量

Question

我想我理解为什么变量存在于它们声明的函数之外,因为你正在返回另一个函数:

myFunction = function() {
    var closure = 'closure scope'
    return function() {
        return closure;
    }
}
A = myFunction(); // myFunction returns a function, not a value
B = A(); // A is a function, which when run, returns:
console.log(B); // 'closure scope'

它现在写的方式,调用A()就像一个getter.

问:如何编写myFunction以便调用A(123)是一个setter？

Answer 1

请尝试以下方法:

myFunction = function() {
    var closure = 'closure scope'

    // value is optional
    return function(value) {
        // if it will be omitted
        if(arguments.length == 0) {
            // the method is a getter
            return closure;
        } else {
            // otherwise a setter
            closure = value;
            // with fluid interface ;)
            return this;
        }
    }
}
A = myFunction(); // myFunction returns a function, not a value
A(123); // set value
B = A(); // A is a function, which when run, returns:
console.log(B); // '123'