使用Javascript在下拉菜單中選擇一個值

Question

$('select[name^="salesrep"] option[value="Bruce Jones"]').attr("selected","selected");

如何在javascript中編寫以上代碼？

Answer 1

您可以如下使用querySelector

 document.querySelector('select[name^="salesrep"] option[value="Bruce Jones"]').selected = true; 

 <select name="salesrep"> <option value="Bruce Jones">Bruce Jones</option> <option value="John Doo">John Doo</option> <option value="John Lee">John Lee</option> <option value="Jane Doo">Jane Doo</option> </select> 

Answer 2

JavaScript：

 var mySelect = document.getElementById('salesrep'); for(var i, j = 0; i = mySelect.options[j]; j++) { if(i.value == 'Bruce Jones') { mySelect.selectedIndex = j; break; } } 

 <select name="salesrep" id="salesrep"> <option value="Bruce Jones">Bruce Jones</option> <option value="John Doo">John Doo</option> <option value="John Lee">John Lee</option> <option value="Jane Doo">Jane Doo</option> </select>