Javascript generates a specified range numerical random number _javascript tips

Source: Internet
Author: User
Tags cdata
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)
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/>
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