[英]Trying to validate username and password in javascript but not getting alert and desired output
請檢查代碼
function validate() { var name = document.getElementById("name"); var pwd = document.getElementById("pwd"); if (name == null || name == "") { alert("Name can't be blank"); return false; } else if (pwd.length < 6) { alert("Password must be at least 6 characters long."); return false; } }
<form> username: <input type="text" id="name"></input> <br> password: <input type="password" id="pwd"></input> <br> <button onclick="validate()">Submit</button> </form>
function validate() { var name = document.getElementById("name").value; var pwd = document.getElementById("pwd").value; if (name === null || name === "") { alert("Name can't be blank"); return false; } else if (pwd.length < 6) { alert("Password must be at least 6 characters long."); return false; } }
<form> username: <input type="text" id="name"></input> <br> password: <input type="password" id="pwd"></input> <br> <button onclick="validate()">Submit</button> </form>
有一種更簡單的方法可以做你想做的事情。 您可以使用form
的原生屬性來發揮自己的優勢:
<form> Username: <input type="text" minlength="2" required> <br> Password: <input type="password" minlength="6" required> <br> <button type="submit">Submit</button> </form>
<!DOCTYPE html>
<html>
<body>
<form>
username: <input type="text" id="name"></input>
<br>
password: <input type="password" id="pwd"></input>
<br>
<button onclick="validate()">Submit</button>
</form>
<script>
function validate() {
var name = document.getElementById("name").value;
var pwd = document.getElementById("pwd").value;
if (name == null || name == "") {
alert("Name can't be blank");
return false;
} else if (pwd.length < 6) {
alert("Password must be at least 6 characters long.");
return false;
}
}
</script>
</body>
</html>
您還沒有提供完整的代碼,所以我們無法真正幫助您。 據我所知,您沒有發出成功驗證的警報。
您需要獲取該值,因此您需要將 add.value 添加到 getElement 函數中。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.