| <html> |
|
| <head> |
| <title> new document </title> ? |
| <script type="text/javascript"> |
| function count(){ |
| var txt1 ? = parseInt( document.getElementById('txt1').value);//獲取第一個(gè)輸入框的值 |
| var txt2 ? = parseInt( document.getElementById('txt2').value);//獲取第二個(gè)輸入框的值 |
| var select = document.getElementById('select').value;//獲取選擇框的值 |
| var result = ''; |
| switch (select) |
| { |
| case '+': |
| result = txt1 + txt2; |
| break; |
| case '-': |
| result = txt1 - txt2; |
| break; |
| case '*': |
| result = txt1 * txt2; |
| break; |
| case '/': |
| result = txt1 / txt2; |
| break; |
| } |
| document.getElementById('fruit').value = result;//設(shè)置結(jié)果輸入框的值 |
| } |
| </script> |
| </head> |
| <body> |
| <input type='text' id='txt1' /> |
| <select id='select'> |
| <option value='+'>+</option> |
| <option value="-">-</option> |
| <option value="*">*</option> |
| <option value="/">/</option> |
| </select> |
| <input type='text' id='txt2' /> |
| <input type='button' value=' ?= ?' ?onclick = "count()" /> |
| <input type='text' id='fruit' /> ? |
| </body> |
| </html> |
2019-01-29
function?count(){ //獲取第一個(gè)輸入框的值 var?num1=parseInt(document.getElementById("txt1").value); //獲取第二個(gè)輸入框的值 var?num2=parseInt(document.getElementById("txt2").value); //獲取選擇框的值 var?oper=document.getElementById("select").value;? //獲取通過下拉框來選擇的值來改變加減乘除的運(yùn)算法則 var?res; switch?(oper){ case?'+':res=num1+num2;?break; case?'-':res=num1-num2;break; case?'*':res=num1*num2;break; case?'/':res=1.0*num1/num2;?break; defalut:break; } //設(shè)置結(jié)果輸入框的值? document.getElementById("fruit").value=res;? } function?count2()?{ document.getElementById("fruit").value?=? eval(document.getElementById("txt1").value?+?document.getElementById("select").value?+?document.getElementById("txt2").value); }