如何驗證 JavaScript 中的多個復選框？

Question

我有 4 個復選框，我想在前兩個被選中但沒有收到 output 時顯示不同的警報。請讓我知道哪里出錯了。

 let ReviewCheckBox = checkform.ratings; if (ReviewCheckBox[0].checked == true) { alert("1 Selected"); } else if (ReviewCheckBox[0].checked == true && ReviewCheckBox[1].checked == true) { alert("Both Selected"); }

 <div> <span>CUSTOMER REVIEWS</span><br> <form name="checkform" onclick="productFilter()"> <input type="checkbox" name="ratings" id="rating-checka"> <label for="rating-checka">4 * & Above</label><br> <input type="checkbox" name="ratings" id="rating-checkb"> <label for="rating-checkb">3 * & Above</label><br> <input type="checkbox" name="ratings" id="rating-checkc"> <label for="rating-checkc">2 * & Above</label><br> <input type="checkbox" name="ratings" id="rating-checkd"> <label for="rating-checkd">1 * & Above</label> </form> </div>

Answer 1

1）您必須驗證選中的每個復選框，因此您可以創建一個 function productFilter並且每次您選中它都會運行

2）您必須首先檢查0和1索引復選框，而only 0 。

 function productFilter() { let ReviewCheckBox = checkform.ratings; if (ReviewCheckBox[0].checked == true && ReviewCheckBox[1].checked == true) { alert("Both Selected"); } else if (ReviewCheckBox[0].checked == true) { alert("1 Selected"); } }

 <div> <span>CUSTOMER REVIEWS</span><br> <form name="checkform" onclick="productFilter()"> <input type="checkbox" name="ratings" id="rating-checka"> <label for="rating-checka">4 * & Above</label><br> <input type="checkbox" name="ratings" id="rating-checkb"> <label for="rating-checkb">3 * & Above</label><br> <input type="checkbox" name="ratings" id="rating-checkc"> <label for="rating-checkc">2 * & Above</label><br> <input type="checkbox" name="ratings" id="rating-checkd"> <label for="rating-checkd">1 * & Above</label> </form> </div>