<!DOCTYPE html><html> <head> <title> 事件</title> <script type="text/javascript"> function count() { var txt1 = parseInt(document.getElementById('txt1').value); //获取第一个输入框的值 var txt2 = parseInt(document.getElementById('txt2').value); //获取第二个输入框的值 var sel = document.getElementById('select').value; //获取选择框的值 var result = ''; if(sel = '+') { result = txt1 + txt2; } else if(sel = '-') { result = txt1 - txt2; } else if(sel = '*'){ result = txt1 * txt2; } else{ result = txt1 / txt2; } document.getElementById('fruit').value = result; } </script> </head> <body> <input type='text' id='txt1' /> <select id='select'> <option value='+'>+</option> <option value="-">-</option> <option value="*">*</option> <option value="/">/</option> </select> <input type='text' id='txt2' /> <input type='button' value=' = ' onclick='count()' /> <!--通过 = 按钮来调用创建的函数，得到结果--> <input type='text' id='fruit' /> </body></html>
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我爱吃牛排
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if(sel = '+') {
result = txt1 + txt2;
} else if(sel = '-') {
result = txt1 - txt2;
} else if(sel = '*'){
result = txt1 * txt2;
}
改为
if(sel == '+') {
result = txt1 + txt2;
} else if(sel == '-') {
result = txt1 - txt2;
} else if(sel == '*'){
result = txt1 * txt2;
}
少等号了你
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