javascript| Random Description:
I originally thought that the random number of Js should be nothing, look up the handbook.
After looking up the handbook, I know that the information presented is poor, and there are no random numbers to generate M-n range ..., just give you a math.random ().
But after my little efforts, finally let me touch the doorway, the problem is taken for granted.
And then you write a formula that should get rid of the usage, the formula:
1. Starting from 1 to any value
linenum
- parseint (Math.random () * Upper limit + 1);
2. Start from any value to any value
linenum
- parseint (Math.random () * (upper-bound + 1) + lower bound);
The formula above uses parseint (), so add 1; If you use Math.ceil () you do not need to add 1, I am used to writing ...
Directory:
1. Demo 1 (direct generate random number operation)
2. Demo 2 (write function to generate random number operation)
Shawl.qiu
2006-10-28
Http://blog.csdn.net/btbtd
1. Demo 1 (direct generate random number operation)
LineNum
- <script type= "Text/javascript" >
- <! [cdata[
- Window.onload=function () {
- var n=na=nb=nc= ';
- N=parseint (Math.random () *10+1);
- Na=parseint (Math.random () * (20-11+1) + 11);
- Nb=parseint (Math.random () *100+1);
- Nc=parseint (Math.random () * (100-51+1) + 51);
- var o=document.getelementsbytagname (' input ');
- O[0].value=n;
- O[1].value=na;
- O[2].VALUE=NB;
- O[3].VALUE=NC;
- }//Shawl.qiu script
- ]]>
- </script>
- 1-10: <input type= "text"/><br/>
- 11-20: <input type= "text"/><br/>
- 1-100: <input type= "text"/><br/>
- 51-100: <input type= "text"/><br/>
2. Demo 2 (write function to generate random number operation)
LineNum
- <script type= "Text/javascript" >
- <! [cdata[
- Window.onload=function () {
- var o=document.getelementsbytagname (' input ');
- O[0].value=frandomby (10);
- O[1].value=frandomby (11, 20);
- O[2].value=frandomby (1, 100);
- O[3].value=frandomby (51, 100);
- }
- function Frandomby (under, over) {
- Switch (arguments.length) {
- Case 1:return parseint (Math.random () *under+1);
- Case 2:return parseint (Math.random () * (over-under+1) + under);
- Default:return 0;
- }
- }//Shawl.qiu script
- ]]>
- </script>
- 1-10: <input type= "text"/><br/>
- 11-20: <input type= "text"/><br/>
- 1-100: <input type= "text"/><br/>
- 51-100: <input type= "text"/><br/>