测试没问题，出错的同学可以参考哈！

源自：6-11 编程练习

<!DOCTYPE html>

<html>

<head>

function count(){

var x = parseInt(document.getElementById("txt1").value);

var y = parseInt(document.getElementById("txt2").value);

var s = document.getElementById("select").value;

var z = document.getElementById("fruit").value;

switch(s){

case "+":

z= x + y;

break;

case "-":

z= x - y;

break;

case "*":

z= x * y;

break;

case "/":

z= x / y;

break;

}

document.getElementById("fruit").value = z;

}

</script>

</head>

<body>

</select>

</body>

</html>

提问者：慕婉清9404838 2020-07-18 22:37