                        課程
                    
                        /前端開發(fā)
                        
                            /JavaScript
                        
                        /JavaScript進(jìn)階篇

請問我哪里錯了呀？實(shí)在找不出來，現(xiàn)在點(diǎn)=不出結(jié)果

<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title> ?
? <script type="text/javascript">
?? function count(){
????? ?
??? //獲取第一個輸入框的值
??? var num1=document.getElementById("txt1").value;
?? ?//獲取第二個輸入框的值
??? var num2=document.getElementById("txt2").value;
?? var num3=document.getElementById("select").value;
?? var num4:
?? ?//獲取選擇框的值
??? switch(num3){
??? case "+":num4=parseInt(num1)+parseInt(num2);break；
??? case "-":num4=parseInt(num1)-parseInt(num2);break；
??? case "*":num4=parseInt(num1)*parseInt(num2);break；
??? case "/":num4=parseInt(num1)/parseInt(num2);break；
??? }
document.getElementById("fruit")=num4;
?
?? }
? </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=' = ' onclik="count()"/> 
?? <input type='text' id='fruit' />? ?
?</body>
</html>

么小么

2015-05-27

源自：JavaScript進(jìn)階篇 6-11

關(guān)注問題我要回答

1010

操作

收起

2 回答

成者并非一蹴而就
2015-05-27

<!DOCTYPE?html>
<html>
?<head>
??<title>?事件</title>
??<meta?http-equiv="Content-Type"?content="text/html;charset=UTF-8">
??<script?type="text/javascript">
???function?count(){
?????/**?獲取ID的值?*/
????var?num1?=?document.getElementById("txt1").value;
????var?num2?=?document.getElementById("txt2").value;
????var?num3?=?document.getElementById("select").value;
????var?num4?=?"";
????/*進(jìn)行判斷運(yùn)算*/
????switch(num3)?{
????????case?"+":
????????????num4?=?parseInt(num1)?+?parseInt(num2);
????????????break;
????????case?"-":
????????????num4?=?parseInt(num1)?-?parseInt(num2);
????????????break;
????????case?"*":
????????????num4?=?parseInt(num1)?*?parseInt(num2);
????????????break;
????????case?"/":
????????????num4?=?parseInt(num1)?/?parseInt(num2);
????????default:
??????????????alert("Are?you?kidding?me!!!");
????}
????//得到的結(jié)果反饋給fruit,也就是value..在頁面看到結(jié)果
????document.getElementById("fruit").value?=?num4;

???}
??</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()?/>?<!--通過?=?按鈕來調(diào)用創(chuàng)建的函數(shù)，得到結(jié)果-->
???<input?type='text'?id='fruit'?/>
?</body>
</html>