typeof / cunstructor / instanceof

よくわからん

by ethertank

JavaScript

var echoThisConstructor = function(arr) {
    for(var i = 0, l = arr.length; i < l; ++i){        
        document.write( arr[i].constructor + "<br />");
    }
    document.write("<hr \/>");
};

var echoTypeOfThis = function(arr) {
    for(var i = 0, l = arr.length; i < l; ++i){        
        document.write(typeof arr[i] + "<br />");
    }
    document.write("<hr \/>");
};

var echoIsThisInstanceOfObject = function(arr) {
    for(var i = 0, l = arr.length; i < l; ++i){        
        document.write((arr[i] instanceof Object) + "<br />");
    }
    document.write("<hr \/>");
};

var a = [
    "a",
    new String(),
    1..constructor,
    new Number(),
    NaN,
    new Date().getDate(),
    [],
    new Array(),
    {},
    new Object(),
    (function(){}),
    new Function(),
    /aaa/,
    new RegExp(),
    new Date(),
    false,
    true,
    new Boolean(),
    window,
    document.createElement("div"),
    document.createElement("form"),
    document.createElement("canvas").getContext("2d")
];

    
echoThisConstructor(a);

echoTypeOfThis(a);

echoIsThisInstanceOfObject(a);