Published
Edited
Mar 11, 2018
1 star
{
var a = 1;
function b() {
a = 5;
console.log(a) // ?? a
function a() {}
}
b()
}
{
var num1 = 5,
num2 = 10,
result = num1+++num2;
console.log(num1)
console.log(num2)
console.log(result)
// ?? num1, num2, result
}
{
window.x = 5;
var o = {
x: 10,
doIt: function doIt(){
var x = 20;
setTimeout(function(){
console.log(this.x);
}, 10);
}
};
o.doIt();
}
{
var num1 = "10",
num2 = "9";
console.log(num1 < num2) // 字符串比较按字母顺序
console.log(+num1 < num2) // 字符串和数字比，将字符串转换为数字比较
console.log(num1 + num2) // 字符串相加
console.log(+num1 + num2) // 字符串相加
}
{
var message = "Hello world!";
console.log(message.substring(1, 4))
console.log(message.substr(1,4))
}
{
var o = {
x: 8,
valueOf: function(){
return this.x + 2;
},
toString: function(){
return this.x.toString();
}
},
result = o < "9";
console.log(o.toString());
console.log(result);
}
{
if (!("a" in window)) {
var a = 1;
}
console.log(a);
}
{
var a = 1,
b = function a(x) {
x && a(--x);
};
console.log(a);
}
{
function a(x) {
return x * 2;
}
var a;
console.log(a);
}
{
function a(){
return 1;
}
var a = 1;
console.log(a);
}
{
function b(x, y, a) {
arguments[2] = 10;
console.log(a); // 10 in all browser; if 'use strict', 3
}
b(1, 2, 3);
}
{
function a() {
console.log(this);// window
}
a.call(null);
}
{
var a = (function(){
return typeof arguments;
})();
console.log(a)
}
{
var f = function g(){ return 23; };
console.log(typeof g())
}
{
var a = (function(x){
delete x;
return x;
})(1);
console.log(a)
}
{
var y = 1, x = y = typeof x;
console.log(x);
}
{
var a = (function f(f){
return typeof f();
})(function(){ return 1; });
console.log(a)
}
{
var foo = {
bar: function() { return this.baz; },
baz: 1
};
var a = (function(){
return typeof arguments[0]();
})(foo.bar);
console.log(a)
}
{
var foo = {
bar: function(){ return this.baz; },
baz: 1
}
console.log(typeof (f = foo.bar)());
}
{
var f = (function f(){ return "1"; }, function g(){ return 2; })();
console.log(typeof f)
}
{
var x = 1;
if (function f(){}) {
x += typeof f;
}
console.log(x)
}
{
var x, y;
var x = [typeof x, typeof y][1];
console.log(typeof typeof x);
}
{
var a = (function(foo){
return typeof foo.bar;
})({ foo: { bar: 1 } });
console.log(a)
}
{
var a = (function f(){
function f(){ return 1; }
return f();
function f(){ return 2; }
})();
console.log(a)
}
{
function f(){ return f; }
console.log(new f() instanceof f)
}
{
with (function(x, undefined){}) { console.log(length);}
}
{
var a = (function f(){
var f
function f(){ return 1; }
return f();
// var f = '123'
function f(){ return 2; }
})();
console.log(a)
}
{
var a = (function f(){
var f = '1'
function f(){ return 1; }
return f();
// var f = '123'
function f(){ return 2; }
})();
console.log(a)
}
{
var a = (function f(){
//var f = 1
function f(){ return 1; }
return f();
var f = '123'
function f(){ return 2; }
})();
console.log(a)
}
{
function a() {
var a = 10;
if(a > 5) {
a = 7;
}
console.log(a);
}
a()
}
{
function a() {
if(true) {
var a = 5;
}
console.log(a);
}
a()
}
{
function first() {
window.a = 3;
}
function second() {
console.log(a);
}
first();
second();
}
{
var a = 5;
function b() {
var a = 7;
console.log(a);
}
b()
}
{
var a = 6;
function test() {
var a = 7;
function again() {
var a = 8;
console.log(a); // First
}
again();
console.log(a); // Second
}
test();
console.log(a); // Third
}
{
function getFunc() {
var a = 7;
return function(b) {
console.log(a+b);
}
}
var f = getFunc();
f(5);
}
{
console.log(typeof typeof(null))
}
{
console.log(100['toString']['length']);
console.log('asdf'['toString']['length']);
}
{
var a = (1,5 - 1) * 2;
console.log(a)
}
{
var x = 10;
var foo = {
x: 20,
bar: function () {
var x = 30;
return this.x;
}
};
console.log(
foo.bar(),
(foo.bar)(),
(foo.bar = foo.bar)(),
(foo.bar, foo.bar)()
);
}
{
function f(x, y) {
x = 10;
console.log(
arguments[0],
arguments[1]
);
}
f();
}
{
var
b = 10,
c = (
20,
function (x) { return x + 100},
function () { return arguments[0]}
);
var a = b + c
console.log(a)
console.log( ({x: 10}).x)
}
{
({
x: 10,
foo: function () {
function bar() {
console.log(x);
console.log(y);
console.log(this.x);
}
with (this) {
var x = 20;
var y = 30;
bar.call(this);
}
}
}).foo();
}
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