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copied!<p>The most common case is this:</p> <pre><code>class foo{ private: int x; int y; public: foo(int _x, int _y) : x(_x), y(_y) {} } </code></pre> <p>This will set <code>x</code> and <code>y</code> to the values that are given in <code>_x</code> and <code>_y</code> in the constructor parameters. This is often the best way to construct any objects that are declared as data members.</p> <p>It is also possible that you were looking at constructor chaining:</p> <pre><code>class foo : public bar{ foo(int x, int y) : bar(x, y) {} }; </code></pre> <p>In this instance, the class's constructor will call the constructor of its base class and pass the values <code>x</code> and <code>y</code>.</p> <p>To dissect the function even further:</p> <pre><code>TransparentObject::TransparentObject( int w, int x, int y, int z ) : _someMethod( 0 ), _someOtherMethod( 0 ), _someOtherOtherMethod( 0 ), _someMethodX( 0 ) { int bla; int bla; } </code></pre> <p>The <code>::</code>-operator is called the scope resolution operator. It basically just indicates that <code>TransparentObject</code> is a member of <code>TransparentObject</code>. Secondly, you are correct in assuming that the body of the constructor occurs in the curly braces.</p> <blockquote> <p>UPDATE: Thanks for the answers. May those be called methods? ( I guess no ) and what is the difference of call them within the constructor body</p> </blockquote> <p>There is much more information on this subject than I could possibly ever give you <a href="http://www.parashift.com/c++-faq-lite/ctors.html#faq-10.6" rel="noreferrer">here</a>. The most common area where you have to use initializer lists is when you're initializing a reference or a <code>const</code> as these variables must be given a value immediately upon creation.</p>

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