Introduction Solution The mysql_* functions in PHP are deprecated and no longer supported. They are also vulnerable to SQL injection attacks, which can be used to gain access to sensitive data. Additionally, the mysql_* functions are not compatible with the newer versions of PHP, so using them can lead to compatibility issues. For these reasons, … Read more
The stack is the memory set aside as scratch space for a thread of execution. When a function is called, a block is reserved on the top of the stack for local variables and some bookkeeping data. When that function returns, the block becomes unused and can be used the next time a function is … Read more
Compiling a C++ program takes place in several steps, as specified by 2.2 (credits to Keith Thompson for the reference): The precedence among the syntax rules of translation is specified by the following phases [see footnote]. Physical source file characters are mapped, in an implementation-defined manner, to the basic source character set (introducing new-line characters … Read more
–> is not an operator. It is in fact two separate operators, — and >. The conditional’s code decrements x, while returning x‘s original (not decremented) value, and then compares the original value with 0 using the > operator. To better understand, the statement could be written as follows: while( (x–) > 0 ) 4 … Read more
Introduction The “->” operator in C++ is a dereferencing operator that is used to access the members of a class or structure. It is also known as the arrow operator and is used to access the members of a pointer to a class or structure. This operator is used to access the members of a … Read more
Notice / Warning: 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 … Read more
Undo git add for uncommitted changes with: git reset <file> That will remove the file from the current index (the “about to be committed” list) without changing anything else. To unstage all changes for all files: git reset In old versions of Git, the above commands are equivalent to git reset HEAD <file> and git … Read more
The Definitive C++ Book Guide and List solved The Definitive C++ Book Guide and List
To rename a branch while pointed to any branch: git branch -m <oldname> <newname> To rename the current branch: git branch -m <newname> -m is short for –move. To push the local branch and reset the upstream branch: git push origin -u <newname> To delete the remote branch: git push origin –delete <oldname> To create … Read more
== tests for reference equality (whether they are the same object). .equals() tests for value equality (whether they are logically “equal”). Objects.equals() checks for null before calling .equals() so you don’t have to (available as of JDK7, also available in Guava). Consequently, if you want to test whether two strings have the same value you … Read more
Find the index of the array element you want to remove using indexOf, and then remove that index with splice. The splice() method changes the contents of an array by removing existing elements and/or adding new elements. const array = [2, 5, 9]; console.log(array); const index = array.indexOf(5); if (index > -1) { // only … Read more
Binary floating point math is like this. In most programming languages, it is based on the IEEE 754 standard. The crux of the problem is that numbers are represented in this format as a whole number times a power of two; rational numbers (such as 0.1, which is 1/10) whose denominator is not a power … Read more
For JSON text: application/json The MIME media type for JSON text is application/json. The default encoding is UTF-8. (Source: RFC 4627) For JSONP (runnable JavaScript) with callback: application/javascript Here are some blog posts that were mentioned in the relevant comments: Why you shouldn’t use text/html for JSON Internet Explorer sometimes has issues with application/json A rather … Read more
What is the cause? Bottom Line You are trying to use something that is null (or Nothing in VB.NET). This means you either set it to null, or you never set it to anything at all. Like anything else, null gets passed around. If it is null in method “A”, it could be that method … Read more
To understand what yield does, you must understand what generators are. And before you can understand generators, you must understand iterables. Iterables When you create a list, you can read its items one by one. Reading its items one by one is called iteration: >>> mylist = [1, 2, 3] >>> for i in mylist: … Read more