js实现随机的四则运算题目

时间：2023-03-09 06:26:51
js实现随机的四则运算题目

老师给出的题，写一个小程序，可以生成随机的四则运算题目给给小学生用。以前自己就写了一个四则运算的简单js小程序，是这样的：

事件

+
-
*
/

这是个自己输入的算法，但要求是自动产生随机数。于是我用产生随机数的函数重新写了一个：

new document

题目如下
开始生成题目

这样就可以自动的生成随机的30个四则运算题目了。但是还是有问题，小学生啊！他们不知道负数，不知道小数。所以还要加入判定条件！

switch(Arr[n]){

                case "+":{

                sum=a+b;

                break;

                }

                case "-":{

                sum=a-b;

                while(sum<0){

                    var a = GetRandomNum(1,30);

                    var b = GetRandomNum(1,30);

                    sum=a-b;

                }

                break;

                }

                case "*":{

                sum=a*b;

                break;

                }

                case "/":{

                sum=a/b;

                while(hasDot(sum)){

                        var a = GetRandomNum(1,100);

                        var b = GetRandomNum(1,100);

                        sum=a/b;

                    }

                break;

                }

这样负数和小数都没有了。

不过，小学生貌似会分数的运算。于是我又开始试试写分数的。

 <body> 
<button class="btn btn-success btn-sm" type='button' onclick="pl_f()">开始生成题目</button>

 <span id="text_f"></span>

  <script>

  function GetRandomNum(Min,Max)

    {

        var Range = Max - Min;

        var Rand = Math.random();

        return(Min + Math.round(Rand * Range));

    }

    function max_num(x,y) {

        var t;

        while (y) {

            t = x%y;

            x = y;

            y = t;

        }

        return x;

    }

    function fenshu(a,b,p) {

        if (p==1) {

            if (a>b) {

                return a+"/"+b;

            }else if(a<b){

                return a+"/"+b;

            }else {

                return 1;

            }

        }else {

            var x=a/p;

            var y=b/p;

            if(y==1){

                return x;

            }else{

                return x+"/"+y;

            }

        }

    }

    function pl_f() {

        var son_a = GetRandomNum(1,30);

        var par_b = GetRandomNum(1,30);

        var son_c = GetRandomNum(1,30);

        var par_d = GetRandomNum(1,30);

        var X=son_a+"/"+par_b;

        var Y=son_c+"/"+par_d;

        document.write("第一个分数："+X+"<br>");

        document.write("第二个分数"+Y+"<br>");

        max_x=max_num(son_a,par_b);

        max_y=max_num(son_c,par_d);

        document.write("第一个最大公约数"+max_x+"<br>");

        document.write("第二个最大公约数"+max_y+"<br>");

        var N=fenshu(son_a,par_b,max_x);

        var M=fenshu(son_c,par_d,max_y);

        document.write("第一个分数化简："+N+"<br>");

        document.write("第二个分数化简"+M);

    }

 </script>

 </body>

这个可以动态的生成两个分数，然后输出这个分数分子和分母的最大公约数。最后输出分子的最简式。

最后就是将分数放入整数一起了!

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

 <head>

  <title> new document </title>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">

  <meta name="generator" content="editplus" />

  <meta name="author" content="" />

  <meta name="keywords" content="" />

  <meta name="description" content="" />

 </head>

 <body>

 <button type='button' onclick="play_all()">开始生成题目</button>

 <span id="text"></span>

 </body>

 <script>

  function GetRandomNum(Min,Max)

    {

        var Range = Max - Min;

        var Rand = Math.random();

        return(Min + Math.round(Rand * Range));

    }

    function max_num(x,y) {

        var t;

        while (y) {

            t = x%y;

            x = y;

            y = t;

        }

        return x;

    }

    function fenshu(a,b,p) {

        if (p==1) {

            if (a>b) {

                return a+"/"+b;

            }else if(a<b){

                return a+"/"+b;

            }else {

                return 1;

            }

        }else {

            var x=a/p;

            var y=b/p;

            if(y==1){

                return x;

            }else{

                return x+"/"+y;

            }

        }

    }

    function f_count(a,b,c,d) {

            var Arr = ["+","-","*","/"];

            var n = GetRandomNum(0,3);

            switch(Arr[n]){

                case "+":{

                var sum_x=(a*d)+(b*c);

                var sum_y=b*d;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"+"+c+"/"+d+"="+N;

                break;

                }

                case "-":{

                var sum_x=(a*d)-(b*c);

                    while (sum_x<0) {

                        var a = GetRandomNum(1,30);

                        var b = GetRandomNum(1,30);

                        var c = GetRandomNum(1,30);

                        var d = GetRandomNum(1,30);

                        var sum_x=(a*d)-(b*c);

                    }

                var sum_y=b*d;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"-"+c+"/"+d+"="+N;

                break;

                }

                case "*":{

                var sum_x=a*c;

                var sum_y=b*d;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"*"+c+"/"+d+"="+N;

                break;

                }

                case "/":{

                var sum_x=a*d;

                var sum_y=b*c;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"÷"+c+"/"+d+"="+N;

                break;

                }

            }

    }

    function count(a,b){

            var Arr = ["+","-","*","/"];

            var n = GetRandomNum(0,3);

            switch(Arr[n]){

                case "+":{

                var sum=a+b;

                return a+"+"+b+"="+sum;

                break;

                }

                case "-":{

                var sum=a-b;

                while(sum<0){

                    var a = GetRandomNum(1,30);

                    var b = GetRandomNum(1,30);

                    var sum=a-b;

                }

                return a+"-"+b+"="+sum;

                break;

                }

                case "*":{

                var sum=a*b;

                return a+"*"+b+"="+sum;

                break;

                }

                case "/":{

                var sum=a/b;

                while(a%b!==0){

                    var max_x=max_num(a,b);

                    var N=fenshu(a,b,max_x);

                    return a+"÷"+b+"="+N;

                }

                return a+"÷"+b+"="+sum;

                break;

                }

            }

    }

    function pl_f() {

        var son_a = GetRandomNum(1,30);

        var par_b = GetRandomNum(1,30);

        var son_c = GetRandomNum(1,30);

        var par_d = GetRandomNum(1,30);

        var suma=f_count(son_a,par_b,son_c,par_d);

        return suma;

    }

    function pl() {

            var a = GetRandomNum(1,30);

            var b = GetRandomNum(1,30);

            var sumb=count(a,b);

            return sumb;

    }

    function play_all() {

            for (i = 1; i <=30; i++) {

                var a = GetRandomNum(0,1);

                document.getElementById("text").innerHTML+=("<br>"+"第"+i+"题：");

                switch (a) {

                    case 0:

                        var A=pl();

                        document.getElementById("text").innerHTML+=(A);

                        break;

                    case 1:

                        var B=pl_f();

                        document.getElementById("text").innerHTML+=(B);

                        break;

                }

            }

    }

 </script>

</html>

执行完节目就成这样的啦

js实现随机的四则运算题目

最后上个答案和题目分开的版本！

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

 <head>

  <title> new document </title>

  <meta http-equiv="Content-Type" content="text/html; charset=utf-8">

  <meta name="generator" content="editplus" />

  <meta name="author" content="" />

  <meta name="keywords" content="" />

  <meta name="description" content="" />

 </head>

 <body>

 <button type='button' onclick="play_all()">开始生成题目</button>

 <span id="text"></span>

 <span id="text2"></span>

 </body>

 <script>

  function GetRandomNum(Min,Max)

    {

        var Range = Max - Min;

        var Rand = Math.random();

        return(Min + Math.round(Rand * Range));

    }

    function max_num(x,y) {

        var t;

        while (y) {

            t = x%y;

            x = y;

            y = t;

        }

        return x;

    }

    function fenshu(a,b,p) {

        if (p==1) {

            if (a>b) {

                return a+"/"+b;

            }else if(a<b){

                return a+"/"+b;

            }else {

                return 1;

            }

        }else {

            var x=a/p;

            var y=b/p;

            if(y==1){

                return x;

            }else{

                return x+"/"+y;

            }

        }

    }

    function f_count(a,b,c,d) {

            var Arr = ["+","-","*","/"];

            var n = GetRandomNum(0,3);

            switch(Arr[n]){

                case "+":{

                var sum_x=(a*d)+(b*c);

                var sum_y=b*d;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"+"+c+"/"+d+"="+N;

                break;

                }

                case "-":{

                var sum_x=(a*d)-(b*c);

                    while (sum_x<0) {

                        var a = GetRandomNum(1,30);

                        var b = GetRandomNum(1,30);

                        var c = GetRandomNum(1,30);

                        var d = GetRandomNum(1,30);

                        var sum_x=(a*d)-(b*c);

                    }

                var sum_y=b*d;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"-"+c+"/"+d+"="+N;

                break;

                }

                case "*":{

                var sum_x=a*c;

                var sum_y=b*d;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"*"+c+"/"+d+"="+N;

                break;

                }

                case "/":{

                var sum_x=a*d;

                var sum_y=b*c;

                max_x=max_num(sum_x,sum_y);

                max_y=max_num(sum_x,sum_y);

                var N=fenshu(sum_x,sum_y,max_x);

                return a+"/"+b+"÷"+c+"/"+d+"="+N;

                break;

                }

            }

    }

    function count(a,b){

            var Arr = ["+","-","*","/"];

            var n = GetRandomNum(0,3);

            switch(Arr[n]){

                case "+":{

                var sum=a+b;

                return a+"+"+b+"="+sum;

                break;

                }

                case "-":{

                var sum=a-b;

                while(sum<0){

                    var a = GetRandomNum(1,30);

                    var b = GetRandomNum(1,30);

                    var sum=a-b;

                }

                return a+"-"+b+"="+sum;

                break;

                }

                case "*":{

                var sum=a*b;

                return a+"*"+b+"="+sum;

                break;

                }

                case "/":{

                var sum=a/b;

                while(a%b!==0){

                    var max_x=max_num(a,b);

                    var N=fenshu(a,b,max_x);

                    return a+"÷"+b+"="+N;

                }

                return a+"÷"+b+"="+sum;

                break;

                }

            }

    }

    function pl_f() {

        var son_a = GetRandomNum(1,30);

        var par_b = GetRandomNum(1,30);

        var son_c = GetRandomNum(1,30);

        var par_d = GetRandomNum(1,30);

        var suma=f_count(son_a,par_b,son_c,par_d);

        return suma;

    }

    function pl() {

            var a = GetRandomNum(1,30);

            var b = GetRandomNum(1,30);

            var sumb=count(a,b);

            return sumb;

    }

    function play_all() {

            for (i = 1; i <=30; i++) {

                var a = GetRandomNum(0,1);

                document.getElementById("text").innerHTML+=("<br>"+"第"+i+"题：");

                switch (a) {

                    case 0:

                        var A=pl();

                        var strs = A.split("=");

                        document.getElementById("text").innerHTML+=(strs[0]+"="+"<br>");

                        document.getElementById("text2").innerHTML+=("<br>"+"第"+i+"题答案："+strs[1]);

                        break;

                    case 1:

                        var B=pl_f();

                        var strs = B.split("=");

                        document.getElementById("text").innerHTML+=(strs[0]+"="+"<br>");

                        document.getElementById("text2").innerHTML+=("<br>"+"第"+i+"题答案："+strs[1]);

                        break;

                }

            }

    }

 </script>

</html>

四则最终版开始生成题目

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