1. /*
  2.  * EC(G)
  3.  *   VO(G) / GO
  4.  *     a「window.a」
  5.  * 
  6.  * 变量提升:
  7.  *   var a;
  8.  */
  9. console.log(a); //undefined
  10. if (!('a' in window)) {  //'a' in window===true
  11.   var a = 13;
  12. }
  13. console.log(a); //undefined
  2. /!*
  3.  * EC(G)
  4.  *   fn --> 0x000   {GO}
  5.  * 变量提升: function fn; 声明
  6.  *!/
  7. console.log(fn); //undefined
  8. // fn(); //Uncaught TypeError: fn is not a function
  9. if ('fn' in window) {
  10.     /!*
  11.      * EC(BLOCK)
  12.      *    fn --> 0x000 [[scope]]:EC(BLOCK)
  13.      * 作用域链:<EC(BLOCK),EC(G)>
  14.      * 变量提升:function fn(){...} 声明+定义
  15.      *!/
  16.     fn(); //“哈哈哈”
  17.     function fn() {
  18.         console.log('哈哈哈');
  19.     } //把之前对fn的操作,同步给全局一份
  20. }
  21. fn();  //“哈哈哈”
  1.  /!*
  2.  * EC(G)
  3.  * 变量提升:-- 
  4.  *!/
  5. f = function () {return true;};  //window.f=function...
  6. g = function () {return false;}; //window.g=function...
  7. (function () {
  8.     /!*
  9.      * EC(AN)
  10.      *   g
  11.      * 作用域链:<EC(AN),EC(G)>
  12.      * 形参赋值:--
  13.      * 变量提升:function g; 声明
  14.      *!/
  15.     // g() //报错:g is not a function
  16.     if ([] == ![]) {
  17.         /!* 
  18.          * EC(BLOCK)
  19.          *    g --> 0x000 [[scope]]:EC(BLOCK)
  20.          * 作用域链:<EC(BLOCK),EC(AN)>
  21.          * 变量提升:function g(){...} 声明+定义
  22.          *!/
  23.         f = function () {return false;}  //修改了全局的f值
  24.         function g() {return true;} //EC(AN)中的g --> 0x000
  25.     }
  26. })();
  27. console.log(f()); //false
  28. console.log(g()); //false
  29. // []==![] => []==false => 0==0 => true
  1. function sum(a) { //es6中没有变量提升，但是有一个自我检测的一个机制，在代码自上而下执行前，会先进行检测，
  2.     console.log(a); //经过了词法解析 所以报错
  3.     let a = 100;
  4.     console.log(a);
  5. }
  6. sum(200);
  1. /*
  2.  * EC(G)
  3.  *   obj --> 0x001  => {a:'包子',b:'馒头',name:'珠峰'}
  4.  *   a = 'name'
  5.  *   fn --> 0x000 [[scope]]:EC(G)
  6.  * 变量提升:var obj;  var a;  function fn(obj){...}; 
  7.  */
  8. var obj = {
  9.     a: '包子',
  10.     b: '面条'
  11. };
  12. var a = 'name';
  13. function fn(obj) {
  14.     /*
  15.      * EC(FN)
  16.      *   obj  -->  0x001
  17.      *        -->  0x002  => {1:1}
  18.      * 作用域链:<EC(FN),EC(G)> 
  19.      * 形参赋值:obj=0x001
  20.      */
  21.     console.log(obj); //=>{a:'包子',b:'面条'}
  22.     obj[a] = '珠峰'; //把变量a存储的值作为属性名去操作  obj['name']='珠峰'
  23.     obj.b = '馒头';
  24.     obj = {};
  25.     obj[1] = 1;
  26.     console.log(obj); //=>{1:1}
  27. }
  28. fn(obj); //fn(0x001)
  29. console.log(obj); //=>{a:'包子',b:'馒头',name:'珠峰'}
  1. var i = 5;
  2. function fn(i) {
  3.     return function (n) {
  4.         console.log(n + (++i));
  5.     }
  6. }
  7. var f = fn(1);
  8. f(2);//4
  9. fn(3)(4);//8
  10. fn(5)(6);//12
  11. f(7);//10
  12. console.log(i);//5
  1. var i = 20;
  2. function fn() {
  3.     i -= 2;
  4.     var i = 10;
  5.     return function (n) {
  6.         console.log((++i) - n);
  7.     }
  8. }
  9. var f = fn();
  10. f(1);//console.log(11-1)=>10
  11. f(2);//console.log(++11-2)=>12-2=>10
  12. fn()(3);//console.log(++10-3)=>11-3=>8
  13. fn()(4);//console.log(++10-4)=>11-4=>7
  14. f(5);//console.log(++12-5)=>13-5=>8
  15. console.log(i);//20
  1. let x = 1;
  2. function A(y){
  3.    let x = 2;
  4.    function B(z){
  5.        console.log(x+y+z);
  6.    }
  7.    return B;
  8. }
  9. let C = A(2);
  10. C(3); //7 x=2 y=2 +z=3  2+2+3=7
  1. //EC(G)
  2. //    VO(G)/Go
  3. //        fn======>x001 
  4. //        x====>5
  5. //    f======>X002
  6. //     代码提升
  7. //            fn
  8. let x = 5;
  9. function fn(x) {
  10.     return function(y) {
  11.         console.log(y + (++x));
  12.     }
  13. }
  14. let f = fn(6);
  15. //EC(Fn)
  16. //        x===》6=》7
  17. //        return X002;//{function(y){console.log(y+(++x))}}
  18. f(7); //14 执行 x002(7) 
  19. fn(8)(9);//18
  20. //EC(Fn2)
  21. //    x===>8 9
  22. //    return x003;//{function(y){console.log(y+(++x))}}
  23. //  EC(AN) X003(9)
  24. //        Scope<EC(AN),EC(Fn2)>
  25. //        y=====>9
  26. //            consoloe.log(y+(++x)) 9+9=18
  27. f(10);//15
  28. //x002(10)=>
  29. // EC(f2)
  30. //    Scope<EC(f2),EC(f1)>
  31. //     AO
  32. //        y====10  console.log(y+(++x); 10+8=18
  33. console.log(x);//5
  34. //=>如果去掉function fn(x)的x呢？
  1. let a=0,
  2.     b=0;
  3. function A(a){
  4.     A=function(b){
  5.         alert(a+b++);
  6.     };
  7.     alert(a++);
  8. }
  9. A(1);//2
  10. A(2);//4

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