如何使用javascript检查和更改输入的值

Question

If user types in a value more than 5, I want to set it to 5.

 function maxValCheck() { if (document.getElementById('xxx').value > 5) { document.getElementById('xxx').value = 5; } } 

 <input id="xxx" type="number" onkeypress="maxValCheck()" max="5" min="1" value="1" /> 

Answer 1

只需将事件更改为onkeyup ：

<input id="xxx" type="number" onkeyup="maxValCheck()" max="5" min="1" value="1"/>

Answer 2

You can select the element by getElementById or from the querySelector and need to specify the event that you're going to trigger as the first parameter and second parameter is the function that you're going to execute on the added method in addEventListener.

<input id="xxx" type="number" max="5" min="1" value="1" />

<script>
    const selectElement = document.querySelector('#xxx');
    selectElement.addEventListener('change', function (evt) {
        console.log("value is changing in input");
    });

    // or

    document.getElementById("xxx").addEventListener('change', function (evt) {
        console.log("value is changing in input");
    });
</script>