for和while练习
for：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>for</title>
<script>
var sum = 0;
for(var odd=1;odd < 100; odd++){
if(odd%2!=0){
sum+=odd;
}
}
alert('1-100之间所有奇数之和:'+sum);
var b7s = 0;
var b7n = 0;
for (var i = 1;i<100;i++) {
if (i%7==0) {
b7s+=i;
b7n+=1;
}
}
alert('1-100之间所有7的倍数的总和:'+b7s+'，1-100之间所有7的倍数的个数:'+b7n);
for (var i=100; i<1000; i++) {
var ge = i%10;
var shi = (parseInt(i/10))%10;
var bai = parseInt(i/100);
if(ge**3+shi**3+bai**3==i){
console.log('水仙花数:'+i);
}
}
var iszhi = prompt('输入一个数：');
if(!(+iszhi)|| iszhi=='' || +iszhi<2 || +iszhi!=parseInt(iszhi)){
alert('输入有误。');
}
else{
var flag=true;
for (var i = 2; i < +iszhi/2; i++) {
if (+iszhi%i==0) {
flag=false;
}
}
if (flag){
alert('是质数');
}
else{
alert('不是质数');
}
}
var str='';
for (var i = 1; i <=9 ; i++) {
for (var col = 1; col <= i; col++) {
str += (col+'*'+i+'='+col*i+' ');
}
str += '\n';
}
console.log(str);
var zhi='';
for (var i = 2; i <= 100; i++) {
var flag=true;
for (var b = 2; b <= i/2; b++) {
if (i%b==0) {
flag=false;
break;
}
}
if (flag){
zhi += i+' ';
}
}
console.log(zhi);
</script>
</head>
<body>
</body>
</html>
while：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>while</title>
<script>
var moy = 1000;
var n = 0;
while(moy < 5000){
moy += moy*0.05;
n+=1;
}
alert(n+'年');
do{
var score = prompt('小明成绩：');
}while(!(+score>=0&&+score<=100&&score!=''));
</script>
</head>
<body>
</body>
</html>
