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>mt_rand</A
></H1
><DIV
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NAME="AEN20063"
></A
><P
>    (PHP3 &#62;= 3.0.6, PHP4 )</P
>mt_rand&nbsp;--&nbsp;Generate a better random value</DIV
><DIV
CLASS="refsect1"
><A
NAME="AEN20066"
></A
><H2
>Description</H2
><DIV
CLASS="funcsynopsis"
><A
NAME="AEN20068"
></A
><P
></P
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="function"
>mt_rand</B
></CODE
> ([int
       min [, int
       max]])</CODE
></P
><P
></P
></DIV
><P
>&#13;     Many random number generators of older libcs have dubious or
     unknown characteristics and are slow. By default, PHP uses the
     libc random number generator with the <A
HREF="function.rand.html"
><B
CLASS="function"
>rand()</B
></A
>
     function.  <B
CLASS="function"
>mt_rand()</B
> function is a drop-in
     replacement for this.  It uses a random number generator with
     known characteristics, the Mersenne Twister, which will produce
     random numbers that should be suitable for seeding some kinds
     of cryptography (see the home pages for details) and is four
     times faster than what the average libc provides. The Homepage
     of the Mersenne Twister can be found at
     <A
HREF="http://www.math.keio.ac.jp/~matumoto/emt.html"
TARGET="_top"
>http://www.math.keio.ac.jp/~matumoto/emt.html</A
>, and an
     optimized version of the MT source is available from
     <A
HREF="http://www.scp.syr.edu/~marc/hawk/twister.html"
TARGET="_top"
>http://www.scp.syr.edu/~marc/hawk/twister.html
     </A
>.
    </P
><P
>&#13;     If called without the optional <TT
CLASS="parameter"
><I
>min</I
></TT
>,
     <TT
CLASS="parameter"
><I
>max</I
></TT
> arguments <B
CLASS="function"
>mt_rand()</B
>
     returns a pseudo-random value between 0 and
     <TT
CLASS="constant"
>RAND_MAX</TT
>.  If you want a random number
     between 5 and 15 (inclusive), for example, use <TT
CLASS="literal"
>mt_rand
     (5, 15)</TT
>.
    </P
><P
>&#13;     Remember to seed the random number generator before use with
     <A
HREF="function.mt-srand.html"
><B
CLASS="function"
>mt_srand()</B
></A
>.
    </P
><DIV
CLASS="note"
><BLOCKQUOTE
CLASS="note"
><P
><B
>Note: </B
>
      In versions before 3.0.7 the meaning of
      <TT
CLASS="parameter"
><I
>max</I
></TT
> was <TT
CLASS="parameter"
><I
>range</I
></TT
>. To
      get the same results in these versions the short example should
      be <TT
CLASS="literal"
>mt_rand (5, 11)</TT
> to get a random number
      between 5 and 15.
     </P
></BLOCKQUOTE
></DIV
><P
>&#13;     See also <A
HREF="function.mt-srand.html"
><B
CLASS="function"
>mt_srand()</B
></A
>,
     <A
HREF="function.mt-getrandmax.html"
><B
CLASS="function"
>mt_getrandmax()</B
></A
>, <A
HREF="function.srand.html"
><B
CLASS="function"
>srand()</B
></A
>,
     <A
HREF="function.rand.html"
><B
CLASS="function"
>rand()</B
></A
> and <A
HREF="function.getrandmax.html"
><B
CLASS="function"
>getrandmax()</B
></A
>.
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