javascript - 如果输入 a 或 b 正确/正确，我如何执行操作？

Question

这个问题已经有答案了:

How to do case insensitive string comparison? (23 个回答)

已关闭 3 年前。

用户在我的输入栏中写入“足球”，然后执行第 6 行和第 7 行的操作。
但如果用户用大写字母写“Football”怎么办？我试图实现“逻辑或” ||但我无法让它工作。

var input = document.getElementById("user_input");
let footballTeams = ["Manchester","Barcelona","Copenhagen"]

if (input.value == "football") {
    alert("These cities have football teams:" +
          "\n" + footballTeams[0] + "," + " " + footballTeams[1] + "," + " " + footballTeams[2])

Answer 1

试试这个:

if (input.value.toLowerCase() == "football")