<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
</body>
</html>
<script type="text/javascript">
//随机数 js中默认产生0~1
var a=Math.random();
document.write(a+"<br />");
//范围[0~20]
//规则 [0~n] random()*n+1
a=Math.floor(Math.random()*21);
document.write(a+"<br />");
//范围[20~90]
//规则 [m~n] random()*(m-n+1)+m
a=Math.floor(Math.random()*71+20);
document.write(a+"<br />");
document.write("练习1<br />");
var b=0;
for(var i=1;i<=10;i++){
a=Math.floor(Math.random()*61+30);
document.write(a+"<br />");
b+=a;
}
document.write("和等于"+b+"<br />");
document.write("练习2<br />");
var a=0,b=0,c=70;
for(var i=1;i<=10;i++){
a=Math.floor(Math.random()*51+20);
document.write(a+"<br />");
var d=a>b?a:b;
b=d;
var e=a<c?a:c;
c=e;
}
document.write("最大值"+d+"<br />");
document.write("最小值"+e+"<br />");
document.write("练习3<br />");
var a=0,max=0,min=70;
for(var i=1;i<=10;i++){
temp=Math.floor(Math.random()*51+20);
document.write(temp+"<br />");
var max=temp>max?temp:max;
var min=temp<min?temp:min;
}
document.write("最大值"+max+"<br />");
document.write("最小值"+min+"<br />");
document.write("练习3<br />");
var max=0,min=80,max_index=0,min_index=0;
for(var i=1;i<=10;i++){
temp=Math.floor(Math.random()*71+10);
document.write(temp+"<br />");
if(max<temp){
max=temp;
max_index=i;
}
if(min>temp){
min=temp;
min_index=i;
}
}
document.write("最大值"+max+"<br />");
document.write("在第"+max_index+"位<br />");
document.write("最小值"+min+"<br />");
document.write("在第"+min_index+"位<br />");
</script>
运行结果：
