<html lang="en"> <head> <title>Increment Ops - Untitled</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Untitled"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Expressions.html#Expressions" title="Expressions"> <link rel="prev" href="Assignment-Ops.html#Assignment-Ops" title="Assignment Ops"> <link rel="next" href="Operator-Precedence.html#Operator-Precedence" title="Operator Precedence"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="Increment-Ops"></a> <p> Next: <a rel="next" accesskey="n" href="Operator-Precedence.html#Operator-Precedence">Operator Precedence</a>, Previous: <a rel="previous" accesskey="p" href="Assignment-Ops.html#Assignment-Ops">Assignment Ops</a>, Up: <a rel="up" accesskey="u" href="Expressions.html#Expressions">Expressions</a> <hr> </div> <h3 class="section">8.7 Increment Operators</h3> <p><em>Increment operators</em> increase or decrease the value of a variable by 1. The operator to increment a variable is written as ‘<samp><span class="samp">++</span></samp>’. It may be used to increment a variable either before or after taking its value. <p>For example, to pre-increment the variable <var>x</var>, you would write <code>++</code><var>x</var>. This would add one to <var>x</var> and then return the new value of <var>x</var> as the result of the expression. It is exactly the same as the expression <var>x</var><code> = </code><var>x</var><code> + 1</code>. <p>To post-increment a variable <var>x</var>, you would write <var>x</var><code>++</code>. This adds one to the variable <var>x</var>, but returns the value that <var>x</var> had prior to incrementing it. For example, if <var>x</var> is equal to 2, the result of the expression <var>x</var><code>++</code> is 2, and the new value of <var>x</var> is 3. <p>For matrix and vector arguments, the increment and decrement operators work on each element of the operand. <p>Here is a list of all the increment and decrement expressions. <dl> <dt><code>++</code><var>x</var><dd><a name="index-g_t_002b_002b-541"></a>This expression increments the variable <var>x</var>. The value of the expression is the <em>new</em> value of <var>x</var>. It is equivalent to the expression <var>x</var><code> = </code><var>x</var><code> + 1</code>. <br><dt><code>--</code><var>x</var><dd><a name="index-g_t_0040code_007b_002d_002d_007d-542"></a>This expression decrements the variable <var>x</var>. The value of the expression is the <em>new</em> value of <var>x</var>. It is equivalent to the expression <var>x</var><code> = </code><var>x</var><code> - 1</code>. <br><dt><var>x</var><code>++</code><dd><a name="index-g_t_002b_002b-543"></a>This expression causes the variable <var>x</var> to be incremented. The value of the expression is the <em>old</em> value of <var>x</var>. <br><dt><var>x</var><code>--</code><dd><a name="index-g_t_0040code_007b_002d_002d_007d-544"></a>This expression causes the variable <var>x</var> to be decremented. The value of the expression is the <em>old</em> value of <var>x</var>. </dl> </body></html>