摘要：第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題第題屬性是中可表示的最小的數(shù)接近，但不是負(fù)數(shù)。

["1","2","3"].map(parseInt);

[typeof null,null instanceOf Object]

[[3,2,1].reduce(Math.pow),[].reduce(Math.pow)]

var val = "smtg";
console.log("value is" + (val === "smtg") ? "Something" : "Nothing");

var name = "World";
(function(){
    if (typeof name === "undefined") {
        var name = "jack";
        console.log("Goodbye" + name);
    } else {
        console.log("Hello" + name);
    }
})();

var END = Math.pow(2,53);
var START = END - 100;
var count = 0;
for(var i = START; i <= END; i++){
    count++;
}
console.log(count);

var arr = [0,1,2];
arr[10] = 10;
arr.filter(function(x){ return x === undefined});

var two = 0.2;
var one = 0.1;
var eight = 0.8;
var six = 0.6;
[two - one == one, eight - six == two]

function showCase(value){
    switch(value){
        case "A":
            console.log("Case A");
            break;
        case "B":
            console.log("Case B");
            break;
        case undefined:
            console.log("undefined");
            break;
        default:
            console.log("unknown");
            break;
    }
}

showCase(new String("A"))

function showCase(value){
    switch(value){
        case "A":
            console.log("Case A");
            break;
        case "B":
            console.log("Case B");
            break;
        case undefined:
            console.log("undefined");
            break;
        default:
            console.log("unknown");
            break;
    }
}

showCase(String("A"))

function isOdd(num){
    return num % 2 == 1;
}
function isEven(num){
    return num % 2 == 0;
}
function isSane(num){
    return isEven(num) || isOdd(num);
}

var values = [7, 4, "13", -9, Infinity];
values.map(isSane);

Array.isArray(Array.prototype);

var a = [0];
if([0]){
    console.log(a == true);
}else{
    console.log("wut");
}

parseInt(3, 8);
parseInt(3, 2);
parseInt(3, 0);

[] == [];

"5" + 3;
"5" - 3;

1 + - + + + - + 1

var arr = Array(3);
arr[0] = 2;
arr.map(function(item){
    return "1";
});

function sidEffecting(arr){
    arr[0] = arr[2];
}
function bar(a, b, c){
    c = 10;
    sidEffecting(arguments);
    return a + b + c;
}
bar(1,1,1);

var a = 11111111111111000;
var b = 111;
console.log(a + b);

var x = [].reverse;
x();

Number.MIN_VALUE > 0;
// MIN_VALUE 屬性是 JavaScript 中可表示的最小的數(shù)（接近 0 ，但不是負(fù)數(shù)）。它的近似值為 5 x 10-324

[1 < 2 < 3, 3 < 2 < 1];

2 == [[[2]]]

3.toString();
3..toString();
3...toString();

(function(){
    var x = y = 1;
})();
x;
y;

var a = /123/;
var b = /123/;
a == b;
a === b;

var a = [1, 2, 3];
var b = [1, 2, 3];
var c = [1, 2, 4];
a == b;
a === b;
a > c;
a < c;

var a = {};
var b = Object.prototype;
[a.prototype === b, Object.getPrototypeOf(a) === b];

function f(){};
var a = f.prototype, b = Object.getPrototypeOf(f);
a === b;

function foo(){}
var oldName = foo.name;
foo.name = "bar";
[oldName, foo.name];

"1 2 3".replace(/d/g,parseInt);

function f(){}
var parent = Object.getPrototypeOf(f);
f.name; //?
parent.name; //?
typeof eval(f.name) //?
typeof eval(parent.name) //?

var lowerCaseOnly = /^[a-z]+$/;
[lowerCaseOnly.test(null), lowerCaseOnly.test()];

[,,,].join(", ");

var a = {class:"Animal", name:"Fido"};
a.class;

var a = new Date("epoch");

var a = Function.length;
var b = new Function().length;
a === b;

var b = Date(0);
var b = new Date(0);
var c = new Date();
[a === b, b === c, a === c]

var min = Math.min(), max = Math.max();
min < max;

function captureOne(re, str){
    var match = re.exec(str);
    return match && match[1];
}
var numRe = /num=(d+)/ig;
var wordRe = /word=(w+)/i;

a1 = captureOne(numRe, "num=1");
a2 = captureOne(wordRe, "word=1");
a3 = captureOne(numRe, "NUM=2");
a4 = captureOne(wordRe, "WORD=2");

[a1 === a2, a3 === a4]

var a= new Date("2014-03-19");
var b =new Date(2014, 03, 19);
[a.getDay() === b.getDay(), a.getMonth() === b.getMonth()]

if("http://xxxgif.com/picture.jpg".match(".gif")){
    "a gif file"
}else{
    "note a git file"
}

function foo(a){
    var a;
    return a;
}
function bar(a){
    var a = "bye";
    return a;
}
[foo("hello"),bar("hello")];

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