Tutorial by Examples: c

Use putAll to put every member of one map into another. Keys already present in the map will have their corresponding values overwritten. Map<String, Integer> numbers = new HashMap<>(); numbers.put("One", 1) numbers.put("Three", 3) Map<String, Integer> othe...

To begin making modifications to the project's data, you have to obtain a local copy of the versioned project. Use the command line svn client or your favorite SVN client (TortoiseSVN, for example). Your local copy of the project is called a working copy in Subversion and you get it by issuing the c...

You are not the only person working on the project, right? This means that your colleagues are also making modifications to the project's data. To stay up to date and to fetch the modifications committed by others, you should run svn update command in your working copy. As a result, your working cop...

A a pointer to a piece of memory containing n elements may only be dereferenced if it is in the range memory and memory + (n - 1). Dereferencing a pointer outside of that range results in undefined behavior. As an example, consider the following code: int array[3]; int *beyond_array = array + 3; ...

git log -S"#define SAMPLES" Searches for addition or removal of specific string or the string matching provided REGEXP. In this case we're looking for addition/removal of the string #define SAMPLES. For example: +#define SAMPLES 100000 or -#define SAMPLES 100000 git log -G&q...

To delete a remote branch in Git: git push [remote-name] --delete [branch-name] or git push [remote-name] :[branch-name]

If a remote branch has been deleted, your local repository has to be told to prune the reference to it. To prune deleted branches from a specific remote: git fetch [remote-name] --prune To prune deleted branches from all remotes: git fetch --all --prune

A wide variety of standard library functions have among their effects copying byte sequences from one memory region to another. Most of these functions have undefined behavior when the source and destination regions overlap. For example, this ... #include <string.h> /* for memcpy() */ ch...

Requirements: OS X 10.8 “Mountain Lion” or newer required to run Docker. While the docker binary can run natively on Mac OS X, to build and host containers you need to run a Linux virtual machine on the box. 1.12.0 Since version 1.12 you don't need to have a separate VM to be installed, as Docker...

To uninstall one or more locally installed packages, use: npm uninstall <package name> The uninstall command for npm has five aliases that can also be used: npm remove <package name> npm rm <package name> npm r <package name> npm unlink <package name> npm un ...

A group is a section of a regular expression enclosed in parentheses (). This is commonly called "sub-expression" and serves two purposes: It makes the sub-expression atomic, i.e. it will either match, fail or repeat as a whole. The portion of text it matched is accessible in the remai...

Since Groups are "numbered" some engines also support matching what a group has previously matched again. Assuming you wanted to match something where two equals strings of length three are divided by a $ you'd use: (.{3})\$\1 This would match any of the following strings: "abc$...

Evaluates its first operand, and, if the resulting value is not equal to zero, evaluates its second operand. Otherwise, it evaluates its third operand, as shown in the following example: a = b ? c : d; is equivalent to: if (b) a = c; else a = d; This pseudo-code represents it : c...

Evaluates its left operand, discards the resulting value, and then evaluates its rights operand and result yields the value of its rightmost operand. int x = 42, y = 42; printf("%i\n", (x *= 2, y)); /* Outputs "42". */ The comma operator introduces a sequence point between i...

This example uses the Car Table from the Example Databases. SELECT * FROM Cars WHERE TotalCost IN (100, 200, 300) This query will return Car #2 which costs 200 and Car #3 which costs 100. Note that this is equivalent to using multiple clauses with OR, e.g.: SELECT * FROM Cars WHERE TotalCos...

See full documentation on LIKE operator. This example uses the Employees Table from the Example Databases. SELECT * FROM Employees WHERE FName LIKE 'John' This query will only return Employee #1 whose first name matches 'John' exactly. SELECT * FROM Employees WHERE FName like 'John%' Ad...

This example shows how to match an input against several values: def f(x: Int): String = x match { case 1 => "One" case 2 => "Two" case _ => "Unknown!" } f(2) // "Two" f(3) // "Unknown!" Live demo Note: _ is the fall th...

In standard pattern matching, the identifier used will shadow any identifier in the enclosing scope. Sometimes it is necessary to match on the enclosing scope's variable. The following example function takes a character and a list of tuples and returns a new list of tuples. If the character existed...

In order to get const char* access to the data of a std::string you can use the string's c_str() member function. Keep in mind that the pointer is only valid as long as the std::string object is within scope and remains unchanged, that means that only const methods may be called on the object. C++1...

Inheritance works just like it does in other object-oriented languages: methods defined on the superclass are accessible in the extending subclass. If the subclass declares its own constructor then it must invoke the parents constructor via super() before it can access this. class SuperClass { ...