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HTML

              
                

<h1>JavaScript có thể kiểm tra tính hợp lệ của dữ liệu</h1>

<p>Nhập một số từ 1 đến 10:</p>

<input id="numb" type="number">

<button type="button" onclick="myFunction()">Kiểm tra</button>

<p id="demo"></p>

<script>
function myFunction() {
    var x, text;

    // Lấy giá trị trong textbox id="numb"
    x = document.getElementById("numb").value;

    // Nếu x < 1 hoặc >10
    if (isNaN(x) || x < 1 || x > 10) {
        text = "Dữ liệu không hợp lệ";
    } else {
        text = "Dữ liệu hợp lệ";
    }
    document.getElementById("demo").innerHTML = text;
}
</script>
              
            
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JS

              
                
              
            
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