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PHPzCorrection status：qualified
Teacher's comments：可以添加%运算，而且input的类型number如果浏览器不支持的话，就要自动变为text，这个要知道
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<!DOCTYPE html><html lang="en"><head><meta charset="UTF-8"><title>calc</title></head><body><input type="number" name="" id="a_number" value="1"><select name="yunsuanfu" id="yunsuanfu" ><option value="">请选择运算符</option><option value="+" >+</option><option value="-">-</option><option value="*">*</option><option value="/">/</option></select><input type="number" name="" id="b_number">的结果是:<span id="jieguo">【 】</span><br><button id="jisuan" onclick="jisuan()">计算</button></body><script>function jisuan() {var a= document.getElementById("a_number").value;var b= document.getElementById("b_number").value;var yunsuanfu= document.getElementById("yunsuanfu").value;var jieguo ;a = parseFloat(a);b = parseFloat(b);if(isNaN(a) || isNaN(b)){jieguo="请输入数字";}if(yunsuanfu===''){jieguo="还没有选择运算符"}else if(yunsuanfu==='+'){jieguo = a+b;}else if(yunsuanfu==='-'){jieguo = a-b;}else if(yunsuanfu==='*'){jieguo= a*b;}else{if(b===0){jieguo="除数不能为0"}jieguo= a/b;}document.getElementById("jieguo").innerText='【'+ jieguo +'】';}</script></html>
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