Initialization (programming): Difference between revisions

Revision as of 07:10, 31 March 2020

Revision as of 17:56, 11 May 2020

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and not to turn this page into a C++ primer

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<sourcesyntaxhighlight lang="c">

int i = 0;

int k[4] = {0, 1};

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char ty[2] = 'f';

struct Point {int x; int y;} p = { .y = 13, .x = 7 };

</syntaxhighlight>

</source>

C++ examples:

<sourcesyntaxhighlight lang="cpp">

int i2(0);

int j[2] = {rand(), k[0]};

MyClass* xox = new MyClass(0, "zaza");

point q = {0, i + 1};

</syntaxhighlight>

</source>

===Initializer list===

In C++, a [[constructor (object-oriented programming)|constructor]] of a class/struct can have an '''initializer list''' within the definition but prior to the constructor body. It is important to note that when you use an initialization list, the values are not assigned to the variable. They are initialized. In the below example, 0 is initialized into re and im.

Example:

<sourcesyntaxhighlight lang="c">

struct IntComplex {

IntComplex() : re(0), im(0) {}

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int im;

};

</syntaxhighlight>

</source>

Here, the construct <code> : re(0), im(0)</code> is the initializer list.