JS output 和来自 HTML 输入

Question

我有这段代码，我试图让“印象数” element.value 随着用户在预算字段中输入而更新，获得结果的最佳做法是什么？ 展示次数应为预算*350。

<div class="col">
              <div class="input-group">
                <div class="input-group-prepend">
                  <div class="input-group-text">£</div>
                </div>
                <input id="budget" type="text" class="form-control" name="campaign_budget" placeholder="100" value="<?php if(!empty($campaign_budget)) { echo $campaign_budget; } ?>">
              </div>
              <small class="form-text text-muted">You will recieve <span id="impressions">0</span> with this budget.</small>
            </div>

Answer 1

您可以这样做，我使用 static 预算值进行演示，您可以在此处修改并添加您的 PHP 代码。

 const impression = document.getElementById('impressions'); document.getElementById("budget").addEventListener('keyup', (e) => { impression.innerHTML = e.currentTarget.value * 350; });

 <div class="col"> <div class="input-group"> <div class="input-group-prepend"> <div class="input-group-text">£</div> </div> <input id="budget" type="text" class="form-control" name="campaign_budget" placeholder="100" value="50"> </div> <small class="form-text text-muted">You will recieve <span id="impressions">0</span> with this budget.</small> </div>