JavaScript 斐波那契数列 倒序输出 输出100以内的质数代码实例

//求斐波那契数列第n位var n = parseInt(window.prompt('输入你要求的斐波那契数列的位数'));var first = 1,  second = 1,  third;if (n > 2) {  for (var i = 0; i < n - 2; i++) {    third = first + second;    first = second;    second = third;    document.writeln('斐波那契数列的第' + (i + 3) + '位是：' + third)  }} else {  document.writeln(1);}

 //倒序输出 var n = window.prompt("请输入三位数的整数"); for (var i = n.length; i >= 0; i--) {   document.writeln(n.charAt(i)); } document.writeln(a);

//判断是否质数var count = 0; //计数器for (var i = 1; i < 100; i++) {  //看每个i是否质数  for (var j = 1; j <= i; j++) {    if (i % j == 0) {      //统计被整除的次数      count++;    }  }  //如果被整除的次数等于2次，则输出这个数  if (count == 2) {    document.writeln(i + " ");  }  //计数器清零  count=0;}