javascript - jquery 将值放入输入框

Question

我有这个脚本

---

<script>
    function trigger(){
    var x = document.getElementById('xcoord');
    var y = document.getElementById('ycoord');
    var box = document.getElementById('touch');

    if (x.value >= 325 || x.value <= 300 && y.value >= 55 || y.value <= 25) {
    $('#touch').value('passed');

    }

    }  
</script>

---

这是html

---

 <input onchange="trigger()" required type="number" id="xcoord" name="xcoord">
 <input onchange="trigger()" required type="number" id="ycoord" name="ycoord">
 <input required type="text" id="touch" name="touch">

---

我需要在每次 xcoord 和 ycoord 的值符合条件时显示一个值，但即使条件为真也不会打印任何值。

Answer 1

您混合了 JavaScript 和 JQuery。

用JavaScript给输入框赋值

box.value = 'passed';

代码片段

function trigger(){
    var x = document.getElementById('xcoord');
    var y = document.getElementById('ycoord');
    var box = document.getElementById('touch');

    if (x.value >= 325 || x.value <= 300 && y.value >= 55 || y.value <= 25) {
         box.value = 'passed';
    }
}  

<input onchange="trigger()" required type="number" id="xcoord" name="xcoord">
 <input onchange="trigger()" required type="number" id="ycoord" name="ycoord">
 <input required type="text" id="touch" name="touch">

用JQuery给输入框赋值

$('#touch').val('passed'); //Although you already have the box variable

代码片段

 function trigger(){
    var x = document.getElementById('xcoord');
    var y = document.getElementById('ycoord');
    var box = document.getElementById('touch');

    if (x.value >= 325 || x.value <= 300 && y.value >= 55 || y.value <= 25) {
        $('#touch').val('passed');
    }

} 

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<input onchange="trigger()" required type="number" id="xcoord" name="xcoord">
 <input onchange="trigger()" required type="number" id="ycoord" name="ycoord">
 <input required type="text" id="touch" name="touch">

tl;dr;

由于您使用纯 JavaScript 开始编写代码，因此您混淆了如何使用 jQuery 语法更改值。

JavaScript box.value = 'passed';

jQuery $('#touch').val('passed');