#programminginterviewquestionsdaily

If you were not to include the browser would render in quirks mode, which makes the browser’s life difficult. 

This is dependent on what you are using it for. For obvious reasons, “px” is a bad choice for something that is responsive like a shape or picture. But you would use it for a font size. “em” maintains relative size. Which means you have responsive text or it is used widely for paddings or spacing between text blocks. “%” is a very tricky one to use in vertical anything, but it works wonders in horizontal padding or margins. “pt”  is used widely in anything used in print, but isn’t a very responsive design unit. 

Absolute is exactly what it sounds like, you put it in a specific position, wherever you want to placer it. This position effect is actually set relative to the element’s parent, if there is no parent element, then it will be reference to the whole HTML page

When you are making a responsive design webpage, you must list your column choices and sizes from the smallest to largest. Lets say you are making your webpage to be optimized on all four different sections: extra-small, small, medium and large. If you were to put large first, whatever is defaulted inside the code (if you are using frameworks) it would happen that way. For example, when using Bootstrap, if you use all Medium sizes, it will size down to extra small however not small, depending on your design. Having all four choices doesn’t hurt that much download speed, its highly recommended to optimize it for all four, but some have two set designs and use paddings and simple layouts to even out the design, making the UI simple, even if there is not very much items of info or media.

Javascript has two different values for nothing, null and undefined. undefined means that is value is not defined, but could be declared. null means empty or non-existent value, indicates "no-value". 

In simple and plain terms, it is a function that can be stored inside of a variable to be called on later or continuous. It has the special ability to access other variables local to the scope it was created in. Functions like <code>document.onclick</code> is a closure. Why closures are so popular in JS is that they are used a lot for event handling. However keep in mind that a large volume of closures can lead to memory leaks. 

POST is the only one you should ever use for submitting data, since GET might be accessible through a certain Request-URL then.

The browser reads your CSS file from right to left. First looks for all elements matching the key selector (the right-most) Then checks if it matches or is under the next(left-most) element.  If the browser can determine the element you are looking for using just one selector and you've used more, you just have miscellaneous code.