                        課程
                    
                        /前端開發
                        
                            /JavaScript
                        
                        /JavaScript進階篇

沒有結果輸出

<!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?t1?=?document.getElementById("txt1").value;????//獲取第二個輸入框的值????var?t2?=?document.getElementById("txt2").value;????//獲取選擇框的值????var?o1?=?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算法則????//設置結果輸入框的值var?r1?=?"?";switch?(o1){case?"+":r1?=?parseInt(t1)?+?parseInt(t2);break;case?"-":r1?=?parseInt(t1)?-?parseInt(t2);break;case?"*":r1?=?parseInt(t1)?*?parseInt(t2);break;case?"/":r1?=?parseInt(t1)?/?parseInt(t2);break;}document.getElentById("fruit")?=?r1;}</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?=?按鈕來調用創建的函數，得到結果--><input?type='text'?id='fruit'?/>??</body></html>