<body>
Min:<input type="text" placeholder="最小值" class="min">
Max:<input type="text" placeholder="最大值" class="max">
<button onclick="btn()">生成</button>
<input type="text" placeholder="随机数" class="result">
</body>
<script>
function btn() {
var min = document.querySelector('.min');
var minValue = min.value;
var max = document.querySelector('.max');
var maxValue = max.value;
var result = document.querySelector('.result');
var m = Number(minValue) + Math.round(Math.random() * (maxValue - minValue));
result.value = m;
}
</script>