直接给源码:
<!DOCTYPE html>
<html>
<body>
<p id="demo">kkkkkkk </p>
<input id="1" type ="text">
<input id="2" type ="text">
<script>
function mm(){
var x = document.getElementById("1").value;
var y = document.getElementById("2").value;
x = x+y;
document.getElementById('demo').innerHTML = x;
}
</script>
<button onclick="mm()">加和</button>
</body>
</html>
思路:
通过获得框里面的值,然后加和赋给想要的控件,方法为给控件加ID
改变控件显示的方法为.innerHTML = 变量名;
如此牛逼的方法,你慌不慌,啊哈哈哈