“methods in objects are properties too. They just happen to have a function assigned to them.” — Eric Freeman Copy Share Image
“You’ll also hear developers refer to === (strict equality) as the “identity” operator.” — Eric Freeman Copy Share Image
“Remember, null is intended to represent an object that isn’t there.” — Eric Freeman Copy Share Image
“Lexical scope means that we can determine the scope of a variable by reading our code.” — Eric Freeman Copy Share Image
“You can extend your object at any time with new properties. To do this you just specify the new property and give… — Eric Freeman Copy Share Image
“When you declare any kind of global variable or define a global function, it is stored as a property in the window… — Eric Freeman Copy Share Image
“Web Workers have a global function named importScripts that you can use to import one or more JavaScript files into your worker.… — Eric Freeman Copy Share Image
“the truth is JavaScript actually makes two passes over your page: in the first pass it reads all the function definitions, and… — Eric Freeman Copy Share Image
“Now when we use the function keyword this way — that is, within a statement, like an assignment statement — we call… — Eric Freeman Copy Share Image
“There are five falsey values in JavaScript: undefined is falsey. null is falsey. 0 is falsey. The empty string is falsey. NaN… — Eric Freeman Copy Share Image
“Two objects are equal only if the variables containing the object references point to the same object.” — Eric Freeman Copy Share Image
“If you give it an index that is greater than or equal to the length of the string, it returns the empty… — Eric Freeman Copy Share Image
“A callback works like this: give a function to the object that knows about the event. When the event occurs, that object… — Eric Freeman Copy Share Image
“The NoCommand object is an example of a null object. A null object is useful when you don’t have a meaningful object… — Eric Freeman Copy Share Image
“As it turns out, one of the things the new operator does behind the scenes when the object is created is to… — Eric Freeman Copy Share Image
“Q: Q: You said getElementsByTagName returns a list. Do you mean an array? A: A: It returns an object that you can… — Eric Freeman Copy Share Image
“JavaScript creates all local variables at the beginning of a function whether you declare them or not (this is called “hoisting” and… — Eric Freeman Copy Share Image
“when you send an object the worker gets a copy of it. Any changes the worker makes will not affect the object… — Eric Freeman Copy Share Image
“JavaScript: When an event occurs, like the ones you’ve mentioned, that event is added to a queue. I don’t even look at it… — Eric Freeman Copy Share Image
“when you assign a value to a variable name that hasn’t been previously declared, it is treated as a new, global variable.… — Eric Freeman Copy Share Image
“If you assign a new variable without using the var keyword, that variable will be global, even if you are first assigning… — Eric Freeman Copy Share Image
“If you change any property in the prototype, it affects all the objects that inherit from that prototype, unless that object has… — Eric Freeman Copy Share Image
“When you pass zero to setTimeout, you’re asking JavaScript to run your timeout handler as soon as it possibly can — and… — Eric Freeman Copy Share Image
“When you call an object’s method, this is set to the object whose method was called. If the method is not found… — Eric Freeman Copy Share Image
“By lexical scope we mean that JavaScript’s rules for scoping are based purely on the structure of your code (not on some… — Eric Freeman Copy Share Image
“Well, say you write a handler and it requires a lot of computation — that is, something that takes a long time… — Eric Freeman Copy Share Image
“In fact, there’s a keyword in JavaScript named this, and that is exactly how you tell JavaScript you mean this object we’re… — Eric Freeman Copy Share Image
“An object named arguments is available in every function when that function is called. You” — Eric Freeman Copy Share Image
“Remember what happens when you call getElementById and the id doesn’t exist in the DOM? You get null. Same thing with getAttribute.… — Eric Freeman Copy Share Image
“using constructors still doesn’t prevent us from changing an object into something else later, because” — Eric Freeman Copy Share Image
“When you link to multiple JavaScript files from your page, all the global variables are defined in the same global space.” — Eric Freeman Copy Share Image
“JavaScript: Don’t judge me by my bad parts, learn the good stuff and stick with that!” — Eric Freeman Copy Share Image
“JavaScript doesn’t have a classical object-oriented model, where you create objects from classes. In fact, JavaScript doesn’t have classes at all. In… — Eric Freeman Copy Share Image
“When you delete a property, you’re not just deleting the value of the property, you’re deleting the property itself. And, if you try to… — Eric Freeman Copy Share Image
“when you assign a value to a variable name that hasn’t been previously declared, it is treated as a new, global variable. So be… — Eric Freeman Copy Share Image
“Web Workers have a global function named importScripts that you can use to import one or more JavaScript files into your worker. To” — Eric Freeman Copy Share Image
“If the two values have different types, try to convert them into the same type and then compare them” — Eric Freeman Copy Share Image
“Well, it’s a browser policy, and it says you can’t retrieve data from a domain that is different from the domain the page itself… — Eric Freeman Copy Share Image
“Math is not a constructor, or even a function. It’s an object. As you know, Math is a built-in object that you can use… — Eric Freeman Copy Share Image
“When you pass zero to setTimeout, you’re asking JavaScript to run your timeout handler as soon as it possibly can — and this leads… — Eric Freeman Copy Share Image
“JavaScript doesn’t have a character type. So characters are returned as new strings containing one character.” — Eric Freeman Copy Share Image
“Lexical scope means that we can determine the scope of a variable by reading our code.” — Eric Freeman Copy Share Image
“Q: Q: You said getElementsByTagName returns a list. Do you mean an array? A: A: It returns an object that you can treat like… — Eric Freeman Copy Share Image
