代碼感覺是對的但是沒有運行出結(jié)果
<!DOCTYPE html>
<html>
?<head>
? <title> 事件</title>?
? <script type="text/javascript">
?? function count(){
??? var count1= parseInt(document.getElementById("txt1").value);
??? var count2= parseInt(document.getElementById("txt2").value);
??? var select1= document.getElementById("select").value;
??? var result=0;
??? switch(select1){
??????? case "+":
??????????? result=count1+count2;
??????????? break;
??????? case "-":
??????????? result=count1-count2;
??????????? break;
??????? case "*":
??????????? result=count1*count2;
??????????? break;
??????? case "/":
??????????? result=count1/ount2;
??????????? break;??
??? }
??? var result= document.getElementById("fruit").value=result;
??? //獲取第一個輸入框的值
?//獲取第二個輸入框的值
?//獲取選擇框的值
?//獲取通過下拉框來選擇的值來改變加減乘除的運算法則
??? //設(shè)置結(jié)果輸入框的值
???
?? }
? </script>
?</head>
?<body>
?? <input type='text' id='txt1' />
?? <input type='text' id='txt2' />
?? <select id='select'>
??<option value='+'>+</option>
??<option value="-">-</option>
??<option value="*">*</option>
??<option value="/">/</option>
?? </select>
?? <input type='button' value=' = ' onclick="count()"/>
?? <input type='text' id='fruit' />??
?</body>
</html>
2020-02-19
我運行有結(jié)果