从数组中填充li元素删除重复项并在选中时添加值：false（开/关按钮）

Question

the result is my list is getting bigger every time i call this function. i know i am very close to the solve my problem but im getting really nervous these days. Any help or comment will be appreciated.

function devicesoff() {
var devices = document.querySelectorAll("[id^='device_']");

for (var i = 0; i < devices.length; i++) {

    if (devices[i].checked === false) {

        var ele = devices[i].name;

        var para = document.getElementById("p");
        var list = document.createElement("li");


        var t = document.createTextNode(ele + "\n");

        list.appendChild(t);
        para.appendChild(list);

    }

}

Answer 1

First clear the old devices, then add new ones.

 function devicesOff() { var devices = document.querySelectorAll("[id^='device_']"); var para = document.getElementById("p"); para.innerHTML = ""; // clear old devices first // add new ones for (var i = 0; i < devices.length; i++) { if (devices[i].checked === false) { var ele = devices[i].name; var list = document.createElement("li"); var t = document.createTextNode(ele + "\\n"); list.appendChild(t); para.appendChild(list); } } } 

 <input type="checkbox" id="device_1" name="device_1" /> <input type="checkbox" id="device_2" name="device_2" /> <input type="checkbox" id="device_3" name="device_3" /> <input type="button" value="devicesOff" onclick="devicesOff()" /> <ul id="p"> </ul>