var result_1;//加法functionadd(){alert(1);var a =getFirstNumber();var b =getTwiceNumber();var re =Number( a)+Number( b);sendResult(re);}//减法functionsubtract(){var a =getFirstNumber();var b =getTwiceNumber();var re = a - b;sendResult(re);}//乘法functionride(){var a =getFirstNumber();var b =getTwiceNumber();var re = a * b;sendResult(re);}//除法functiondevide(){var a =getFirstNumber();var b =getTwiceNumber();var re = a / b;sendResult(re);}//给p标签传值functionsendResult(result_1){var num = document.getElementById("result")
num.innerHTML = result_1;}//获取第一位数字functiongetFirstNumber(){var firstNumber = document.getElementById("first").value;return firstNumber;}//获取第二位数字functiongetTwiceNumber(){var twiceNumber = document.getElementById("twice").value;return twiceNumber;}