Is null an instance of anything? No, there is no type which null is an instanceof. 15.20.2 Type Comparison Operator instanceof At run time, the result of the instanceof operator is true if the value of the RelationalExpression is not null and the reference could be cast to the ReferenceType without raising a ClassCastException. Otherwise the result is false. This means that for any type E and R, for any E o, where o == null, o … Read more
There’s no performance difference, as they compile to the same bytecode: Stylistically, I try to avoid not x is y, a human reader might misunderstand it as (not x) is y. If I write x is not y then there is no ambiguity.
The Date object will do what you want – construct one for each date, then compare them using the >, <, <= or >=. The ==, !=, ===, and !== operators require you to use date.getTime() as in to be clear just checking for equality directly with the date objects won’t work I suggest you use drop-downs or some similar constrained form of date entry rather than text boxes, … Read more
Notice: Undefined variable From the vast wisdom of the PHP Manual: Relying on the default value of an uninitialized variable is problematic in the case of including one file into another which uses the same variable name. It is also a major security risk with register_globals turned on. E_NOTICE level error is issued in case of working with uninitialized variables, however not … Read more
Heredoc sounds more convenient for this purpose. It is used to send multiple commands to a command interpreter program like ex or cat The string after << indicates where to stop. To send these lines to a file, use: You could also store these lines to a variable: This stores the lines to the variable named VAR. When printing, remember the … Read more
You can use the @ symbol in front of a string to form a verbatim string literal: You also do not have to escape special characters when you use this method, except for double quotes as shown in Jon Skeet’s answer.
You can use the + operator to combine them: Output:
You need to check for status 0 (as when loading files locally with XMLHttpRequest, you don’t get a status returned because it’s not from a Webserver) And specify file:// in your filename:
You’re missing a return statement. When the compiler looks at your code, it’s sees a third path (the else you didn’t code for) that could occur but doesn’t return a value. Hence not all code paths return a value. For my suggested fix, I put a return after your loop ends. The other obvious spot – adding an else that had a return value to the if-else-if – … Read more
You are only looking at the first li child in the query you have instead of looking for any li child element that may contain the text, ‘Model’. What you need is a query like the following: This query will give you the elements that have a class of featureList with one or more li children that contain the text, ‘Model’.