To do this for any object in JavaScript will not be simple or straightforward. You will run into the problem of erroneously picking up attributes from the object’s prototype that should be left in the prototype and not copied to the new instance. If, for instance, you are adding a clone method to Object.prototype, as some answers depict, … Read more
Q: Is this ok?A: yes Q: Is this expected?Yes, this is expected (if you are using react-redux). Q: Is this an anti-pattern?A: No, this is not an anti-pattern. It’s called “connecting” your component or “making it smart”. It’s by design. It allows you to decouple your component from your state an additional time which increases the modularity of … Read more
Use instead of
It is good programming practice to return an empty array [] if the expected return type is an array. This makes sure that the receiver of the json can treat the value as an array immediately without having to first check for null. It’s the same way with empty objects using open-closed braces {}. Strings, Booleans and integers … Read more
Think of it like you’re just calling JavaScript functions. You can’t use a for loop where the arguments to a function call would go: See how the function tbody is being passed a for loop as an argument – leading to a syntax error. But you can make an array, and then pass that in as an argument: You can basically … Read more
Use: As noted in the comments, the line below works, but it is bugged for Firefox. See URL of type DOMString, readonly.
You need to double escape any RegExp characters (once for the slash in the string and once for the regexp): Otherwise, it looks for the end of the line and ‘TESTONE’ (which it never finds). Personally, I’m not a big fan of building regexp’s using strings for this reason. The level of escaping that’s needed … Read more
Primitives are passed by value, and Objects are passed by “copy of a reference”. Specifically, when you pass an object (or array) you are (invisibly) passing a reference to that object, and it is possible to modify the contents of that object, but if you attempt to overwrite the reference it will not affect the copy of … Read more
What is the difference between the following lines of code? What is a named/anonymous function expression? What is a declared function? How do browsers deal with these constructs differently? What do the responses to a similar question (var functionName = function() {} vs function functionName() {}) not get exactly right?
Flags go at the end. i is for case-Insensitive (or ignore-case)