JavaScript 的範圍溢位和範圍下溢屬性。

範圍下溢 − 如果元素值小於 min 屬性中指定的元素值，則將其設定為true。

範圍溢位 − 如果元素值大於 max 屬性中指定的元素值，則將其設定為true。

以下是 JavaScript 中範圍溢位和範圍下溢屬性的程式碼 −

示例

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   }
   .result {
      font-size: 20px;
      font-weight: 500;
   }
</style>
</head>
<body>
<h1>Range Overflow and Range Underflow property</h1>
Enter a number between 0 to 20<input type="number" class="num" min="0" max="20"
step="1"></div>
<button class="Btn">CHECK</button>
<h3>
Click on the above button to check if the number is between 0 and 20.
</h3>
<div style="color: green;" class="result"></div>
<script>
   let resEle = document.querySelector(".result");
   let numEle = document.querySelector('.num');
   document.querySelector(".Btn").addEventListener("click", () => {
      if(numEle.validity.rangeOverflow){
         resEle.innerHTML = 'Number exceeds the range';
      }
      else if(numEle.validity.rangeUnderflow){
         resEle.innerHTML = 'Number is lower than the range ';
      }
      else{
         resEle.innerHTML = 'Number lies in the range';
      }
   });
</script>
</body>
</html>