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1.if ('m' in window) {2. var m = m && 12;3.}4.console.log(m);1.let n = 10;2.if (!('n' in window)) {3. let n = n + 30;4.}5.console.log(n);复制代码 -
1.let n = 10,2. m = 20;3.~function (n, m) {4. let arg = arguments;5. arg[0] = n || 100;6. arg[1] = m || 200;7. console.log(n, m);8.}(m);9.console.log(n, m);复制代码 -
1.let n = 10,2. m = 20;3.~function (n, m) {4. let arg = arguments;5. arg[0] = n || 100;6. arg[1] = m || 200;7. console.log(n, m);8.}(m);9.console.log(n, m);复制代码 -
1.let ary = [12, 23, 34, 45];2.(function (ary) {3. ary.pop();4. ary = ary.slice(0);5. ary.shift();6. console.log(ary);7.})(ary);8.console.log(ary);复制代码 -
1.let n = 10,2. obj = {n: 20};3.let fn = obj.fn = (function () {4. this.n++;5. n++;6. return function (m) {7. n += 10 + (++m);8. this.n += n;9. console.log(n);10. }11.})(obj.n);12.fn(10);13.obj.fn(10);14.console.log(n, obj.n);复制代码 -
1.let a = {n: 4};2.let b = a;3.b.x = a = {n: 10};4.console.log(a.x);5.console.log(b.x);复制代码 -
1.function C1(name) {2. if (name) this.name = name;3.}4.function C2(name) {5. this.name = name;6.}7.function C3(name) {8. this.name = name || 'join';9.}10.C1.prototype.name = 'Tom';11.C2.prototype.name = 'Tom';12.C3.prototype.name = 'Tom';13.alert(new C1().name + new C2().name + new C3().name);复制代码 - 忽略报错对后面代码的影响
1.let m = 20;2.let Fn = function (n, m) {3. this.n = n;4. this.aa = function () {5. console.log(this.n + (++m));6. }7.};8.Fn.prototype.bb = function () {9. console.log(this.n + m);10.};11.let f1 = new Fn(10, 20);12.Fn.prototype = {13. cc: function () {14. console.log(this.n + m);15. }16.};17.let f2 = new Fn(30);18.console.log(f1.constructor === f2.constructor);19.f1.aa();20.f1.bb();21.f1.cc();22.f2.bb();23.f2.cc();24.f2.__proto__.cc();复制代码 -
console.log(a); var a=12; function fn(){ console.log(a); var a=13; } fn(); console.log(a); 输出的三次分别是多少 A、undefined 12 13 B、undefined undefined 12 C、undefined undefined 13 D、有程序报错复制代码 -
2、console.log(a); var a=12; function fn(){ console.log(a); a=13; } fn(); console.log(a); A、undefined 12 13 B、undefined undefined 12 C、undefined undefined 13 D、有程序报错复制代码 -
3、console.log(a); a=12; function fn(){ console.log(a); a=13; } fn(); console.log(a); 输出的三次分别是多少A、undefined 12 13 B、undefined undefined 12 C、undefined undefined 13 D、有程序报错复制代码 -
4、var foo=1; function bar(){ if(!foo){ var foo=10; } console.log(foo); } bar(); 输出的结果是多少A、1 B、10 C、undefined D、报错复制代码 -
5、var n=0; function a(){ var n=10; function b(){ n++; alert(n); } b(); return b; } var c=a(); c(); alert(n);弹出三次的结果分别是什么？A、1 1 1 B、11 11 0 C、11 12 0 D、11 12 12复制代码 -
6、var a=10,b=11,c=12; function test(a){ a=1;var b=2;c=3; } test(10); alert(a); alert(b); alert(c); 弹出的三个值分别是多少？ A、1 11 3 B、10 11 12 C、1 2 3 D、10 11 3复制代码 -
if(!("a" in window)){ var a=1; } alert(a); 弹出的a的值是？A、1 B、undefined C、报错 D、以上答案都不对复制代码 -
var a=4; function b(x,y,a) { alert(a); arguments[2]=10; alert(a); } a=b(1,2,3); alert(a); 三次弹出的结果是 A、3 3 4 B、3 10 4 C、3 10 10 D、3 10 undefined 复制代码 -
var foo='hello'; (function(foo){ console.log(foo); var foo=foo||'world'; console.log(foo); })(foo); console.log(foo); 三次分别输出什么？A、hello hello hello B、undefined world hello C、hello world world D、以上答案都不正确复制代码 -
var a=9; function fn(){ a=0; return function(b){ return b+a++; } }var f=fn()var m=f(5);alert(m);var n=fn()(5);alert(n); var x=f(5);alert(x);alert(a); 弹出的四次结果？A、6 6 7 2 B、5 6 7 3 C、5 5 6 3 D、以上答案都不正确 复制代码