js函数改变全局变量的值后的作用范围

来源：4-14 项目作业

localhost999

2021-09-21 12:27:07

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>document</title>

</head>
<body>
<input type="text" id="one">
<select id="xuanZe">
<option value="+" id="jia">+</option>
<option value="-" id="jian">-</option>
<option value="x" id="chen">x</option>
<option value="/" id="chu">/</option>
</select>
<input type="text" id="two">
<input type="button" value="=" id="denYu">
<input type="text" id="result">

<script type="text/javascript">
var one =document.getElementById('one');
var two =document.getElementById('two');
var jia =document.getElementById('jia');
var jian =document.getElementById('jian');
var chen =document.getElementById('chen');
var chu =document.getElementById('chu');
var denYu =document.getElementById('denYu');
var xuanZe =document.getElementById('xuanZe');
var result =document.getElementById('result');


var end =0;


denYu.onclick=function(){
if(xuanZe.value=="+"){
end=parseInt(one.value)+parseInt(two.value);
}
else if(xuanZe.value=="-"){
end=one.value-two.value;
}
else if(xuanZe.value=="x"){
end=one.value*two.value;
}
else if(xuanZe.value=="/"){
end=one.value/two.value;
}
result.value=end;
}


</script>
</body>
</html>