<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
<script type="text/javascript">
function calClick(){
var value1=document.getElementById("txt1").value;
var value2=document.getElementById("txt2").value;
// document.getElementById("txt3").value=parseInt(value1,10)+parseInt(value2,10);
document.getElementById("txt3").value=value1+value2;
//为什么做加法不行做减法和乘法就可以呢??
}
</script>
</head>
<body>
<input type="text" id="txt1" />+<input type="text" id="txt2" />
<input type="button" id="btn" value="=" onclick="calClick()" /><input type="text" id="txt3" readonly="readonly" />
</body>
</html>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
<script type="text/javascript">
function calClick(){
var value1=document.getElementById("txt1").value;
var value2=document.getElementById("txt2").value;
// document.getElementById("txt3").value=parseInt(value1,10)+parseInt(value2,10);
document.getElementById("txt3").value=value1+value2;
//为什么做加法不行做减法和乘法就可以呢??
}
</script>
</head>
<body>
<input type="text" id="txt1" />+<input type="text" id="txt2" />
<input type="button" id="btn" value="=" onclick="calClick()" /><input type="text" id="txt3" readonly="readonly" />
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
<script type="text/javascript">
function calClick(){
var value1=document.getElementById("txt1").value;
var value2=document.getElementById("txt2").value;
// document.getElementById("txt3").value=parseInt(value1,10)+parseInt(value2,10);
document.getElementById("txt3").value=parseInt(value1)+parseInt(value2);
//为什么做加法不行做减法和乘法就可以呢??
}
</script>
</head>
<body>
<input type="text" id="txt1" />+<input type="text" id="txt2" />
<input type="button" id="btn" value="=" onclick="calClick()" /><input type="text" id="txt3" readonly="readonly" />
</body>
</html>OK了 亲给好评哦
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
<script type="text/javascript">
function calClick(){
var value1=document.getElementById("txt1").value;
var value2=document.getElementById("txt2").value;
// document.getElementById("txt3").value=parseInt(value1,10)+parseInt(value2,10);
document.getElementById("txt3").value=parseInt(value1)+parseInt(value2);
//为什么做加法不行做减法和乘法就可以呢??
}
</script>
</head>
<body>
<input type="text" id="txt1" />+<input type="text" id="txt2" />
<input type="button" id="btn" value="=" onclick="calClick()" /><input type="text" id="txt3" readonly="readonly" />
</body>
</html>OK了 亲给好评哦
var value2=document.getElementById("txt2").value;
你从文本框获取的值默认是字符串的,而在JS中+号可以用来连接字符串,也可以进行数值的运算,既然你取到的value1,value2是字符串,当然是进行字符串的连接操作,你可以加上parseInt或parseFloat转成数值再运算
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
<script type="text/javascript">
function calClick(){
var value1=document.getElementById("txt1").value;
var value2=document.getElementById("txt2").value;
// document.getElementById("txt3").value=parseInt(value1,10)+parseInt(value2,10);
document.getElementById("txt3").value=parseInt(value1)+parseInt(value2);
//为什么做加法不行做减法和乘法就可以呢??
}
</script>
</head>
<body>
<input type="text" id="txt1" />+<input type="text" id="txt2" />
<input type="button" id="btn" value="=" onclick="calClick()" /><input type="text" id="txt3" readonly="readonly" />
</body>
</html>OK了 亲给好评哦