Analysis of two common situations of js closure

//闭包两种情况  1：函数作为返回值
function fn() {
    var max =10;
    return function bar(x) {
        if(x > max){
          console.log(x)
        }else{
            console.log(666)
        }
    }
}
var f1=fn(),max = 100;
f1(15)    //15
//这里fn()赋给f1,调用f1时，即执行bar函数，此时x=15,
//max的取值需是创建该函数的作用域内，即max=10;最后输出15.

//2：函数作为参数传递
    var max=10,
        fn=function (x) {
            if(x > max){
                console.log(x)
            }else{
                console.log('000')
            }
        };
        (function (f) {
            var max = 100;
            f(15)
        })(fn)
    //这是第二种情况，fn函数作为f参数，f(15)就是执行 fn(15);
    //此时x=15,max的取值应该是创建fn函数的作用域内取，即10，输出结果是15；

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