如何检查更改时的文本输入字符串是否具有大写字母 Javascript

Question

Is there a way to check if a text input, on change, has an uppercase letter, in the string using just javascript (or in combination with regex)?

For example:

const passwordInput = document.querySelector("#password");
passwordInput.addEventListener("change", e => {
    if (e.target.value does not contain an uppercase letter) {
        console.log("Must contain an uppercase letter.")
    }
})

Answer 1

if (e.target.value == e.target.value.toLowerCase()) { }