Editing Operator (computer programming) (section)

=== Semantics ===
The semantics of an operator may significantly differ from that of a normal function. For reference, addition is evaluated like a normal function. For example, <code>x + y</code> can be equivalent to a function <code>add(x, y)</code> in that the arguments are evaluated and then the functional behavior is applied. However, [[Assignment_(computer_science)|assignment]] is different. For example, given <code>a = b</code> the target <code>a</code> is ''not'' evaluated. Instead its value is replaced with the value of <code>b</code>. The [[scope resolution operator|scope resolution]] and element access operators (as in <code>Foo::Bar</code> and <code>a.b</code>, respectively, in the case of e.g. [[C++]]) operate on identifier names; not values.

In C, for instance, the array indexing operator can be used for both read access as well as assignment. In the following example, the  [[increment and decrement operators|increment operator]] reads the element value of an array and then assigns the element value.
<syntaxhighlight lang=c>
++a[i];
</syntaxhighlight>

The C++ <code>&lt;&lt;</code> operator allows for [[fluent interface|fluent]] syntax by supporting a sequence of operators that affect a single argument. For example:
<syntaxhighlight lang=cpp>
cout << "Hello" << " " << "world!" << endl;
</syntaxhighlight>