參考部分資料，編寫一個簡單的計算器案例，雖然完成了正常需求，但是也有不滿之處，待后續(xù)實力提升后再來補充，先把不足之處列出：
1：本來打算只要打開頁面，計算器的輸入框會顯示一個默認(rèn)為0的狀態(tài)，但是在輸入框加入默認(rèn)顯示為0的時候，選擇數(shù)據(jù)輸入時，該0會顯示輸入數(shù)字的前面，例如”0123“，由于能力有限，待后續(xù)實力提升再來補充完善！
2：目前只能實現(xiàn)鼠標(biāo)控制選擇按鈕，待完善鍵盤錄入功能。
3：乘法的那個符號在本來想改成”ד這個符號的，待后續(xù)完善。
附圖片一張：
html部分：
<!DOCTYPE html><html lang="en"><head> <meta charset="utf-8"> <title>計算器</title></head><body onload="onLoad()"><div id="calculator"> <div class="LOGO"> <span class="name">簡單的計算器</span> <span class="verson">@liumobai v1.0</span> </div> <div id="shuRu"> <!--screen輸入欄--> <div class="screen"> <input type="text" id="screenName" name="screenName" class="screen" value="" onfocus="jsq(this)"> </div> </div> <div id="keys"> <!-- operators and other keys --> <!--第一排--> <input type="button" id="7" onclick="jsq(this.id)" value="7" class="buttons"> <input type="button" id="8" onclick="jsq(this.id)" value="8" class="buttons"> <input type="button" id="9" onclick="jsq(this.id)" value="9" class="buttons"> <input type="button" id="Back" onclick="tuiGe()" value="Back" class="buttons"> <input type="button" id="C" onclick="clearNum()" value="C" class="buttons" style="margin-right:0px"> <!--第二排--> <input type="button" id="4" onclick="jsq(this.id)" value="4" class="buttons"> <input type="button" id="5" onclick="jsq(this.id)" value="5" class="buttons"> <input type="button" id="6" onclick="jsq(this.id)" value="6" class="buttons"> <input type="button" id="*" onclick="jsq(this.id)" value="*" class="buttons"> <input type="button" id="/" onclick="jsq(this.id)" value="/" class="buttons" style="margin-right:0px"> <!--第三排--> <input type="button" id="1" onclick="jsq(this.id)" value="1" class="buttons"> <input type="button" id="2" onclick="jsq(this.id)" value="2" class="buttons"> <input type="button" id="3" onclick="jsq(this.id)" value="3" class="buttons"> <input type="button" id="+" onclick="jsq(this.id)" value="+" class="buttons"> <input type="button" id="-" onclick="jsq(this.id)" value="-" class="buttons" style="margin-right:0px"> <!--第四排--> <input type="button" id="0" onclick="jsq(this.id)" value="0" class="buttons"> <input type="button" id="00" onclick="jsq(this.id)" value="00" class="buttons"> <input type="button" id="." onclick="jsq(this.id)" value="." class="buttons"> <input type="button" id="%" onclick="jsq(this.id)" value="%" class="buttons"> <input type="button" id="eva" onclick="eva()" value="=" class="buttons" style="margin-right:0px"> </div> <div class="footer"> <span class="aside">歡迎使用JavaScript計算器</span> <span class="link"> <a href="#" title="聲明" target="_blank">反饋</a> </span> </div></div></body></html>
JS部分：
<script> var num = 0; // 定義第一個輸入的數(shù)據(jù) function jsq(num) { //獲取當(dāng)前輸入 document.getElementById('screenName').value += document.getElementById(num).value; } function eva() { //計算輸入結(jié)果 document.getElementById("screenName").value = eval(document.getElementById("screenName").value); } function clearNum() { //清0 document.getElementById("screenName").value = null; document.getElementById("screenName").focus(); } function tuiGe() { //退格 var arr = document.getElementById("screenName"); arr.value = arr.value.substring(0, arr.value.length - 1); } function onLoad(){ //加載完畢后光標(biāo)自動對應(yīng)到輸入框 document.getElementById("screenName").focus(); }</script>CSS部分：
/*Basic reset*/*{ margin:0; padding:0; box-sizing: border-box; font: 14px Arial,sans-serif;}html{ height:100%; background-color:lightslategrey;}#calculator{ margin: 15px auto; width:330px; height:400px; border: 1px solid lightgray; background-color:darkgrey; padding:15px;}/*LOGO*/.LOGO{ height:20px;}.LOGO .name{ float:left; line-height:30px;}.LOGO .verson{ float:right; line-height:30px;}/*screen*/#shuRu{ margin-top:15px;}.screen{ margin-top:5px; width:300px; height:40px; text-align: right; padding-right:10px; font-size:20px;}#keys{ border:1px solid lightgray; height:223px; margin-top:25px; padding:8px;}#keys .last{ margin-right:0px;}.footer{ margin-top:20px; height:20px;}.footer .link{ float:right;}#keys .buttons{ float:left; width: 42px; height: 36px; text-align:center; background-color:lightgray; margin: 0 17px 20px 0;}接下來再給大家分享一則實例
<html><head> <title>Untitled</title> <style type="text/css"> input[type=button] { width:25px; height:25px; } </style> <script type="text/javascript"> var result=0; var point=false; //判斷是小數(shù)點前還是后 var multiple=0.1; //初始化小數(shù)點后的倍率 var sort=0; //標(biāo)記加減乘除 var temp=0; //記錄上一輪結(jié)果 function onbutton0() //數(shù)字按鈕動作 { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+0; //小數(shù)點前的處理 else //小數(shù)點后的處理 { result=result+multiple*0; multiple=multiple*0.1; } name.value=String(result); } function onbutton1() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+1; else { result=result+multiple*1; multiple=multiple*0.1; } name.value=String(result); } function onbutton2() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+2; else { result=result+multiple*2; multiple=multiple*0.1; } name.value=String(result); } function onbutton3() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+3; else { result=result+multiple*3; multiple=multiple*0.1; } name.value=String(result); } function onbutton4() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+4; else { result=result+multiple*4; multiple=multiple*0.1; } name.value=String(result); } function onbutton5() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+5; else { result=result+multiple*5; multiple=multiple*0.1; } name.value=String(result); } function onbutton6() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+6; else { result=result+multiple*6; multiple=multiple*0.1; } name.value=String(result); } function onbutton7() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+7; else { result=result+multiple*7; multiple=multiple*0.1; } name.value=String(result); } function onbutton8() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+8; else { result=result+multiple*8; multiple=multiple*0.1; } name.value=String(result); } function onbutton9() { var name=document.getElementByIdx_x("show"); if(!point) result=10*result+9; else { result=result+multiple*9; multiple=multiple*0.1; } name.value=String(result); } function onbutton_point() //小數(shù)點按鈕 { var name=document.getElementByIdx_x("show"); point=true; name.value=String(result)+"."; } function onbutton_back() //退格按鈕 { var name=document.getElementByIdx_x("show"); var temp=name.value; name.value=""; for(var i=0;i<temp.length-1;i++) name.value+=temp[i]; } function onbutton_plus() { var name=document.getElementByIdx_x("show"); point=false; multiple=0.1; switch (sort) //遇到下一個操作符時判斷上一個操作符是什么，并進(jìn)行上一個操作符的計算 { //eg:1+2+3= 遇到第二個+時判斷前一個符號，發(fā)現(xiàn)是+則進(jìn)行+運算，得到3賦給result case 1:result=result+temp; break; case 2:result=temp-result; break; case 3:result=temp*result; break; case 4:result=temp/result; break; } sort=1; temp=result; result=0; name.value="0"; } function onbutton_minus() { var name=document.getElementByIdx_x("show"); point=false; multiple=0.1; switch (sort) { case 1:result=result+temp; break; case 2:result=temp-result; break; case 3:result=temp*result; break; case 4:result=temp/result; break; } sort=2; temp=result; result=0; name.value="0"; } function onbutton_mult() { var name=document.getElementByIdx_x("show"); point=false; multiple=0.1; switch (sort) { case 1:result=result+temp; break; case 2:result=temp-result; break; case 3:result=temp*result; break; case 4:result=temp/result; break; } sort=3; temp=result; result=0; name.value="0"; } function onbutton_div() { var name=document.getElementByIdx_x("show"); point=false; multiple=0.1; switch (sort) { case 1:result=result+temp; break; case 2:result=temp-result; break; case 3:result=temp*result; break; case 4:result=temp/result; break; } sort=4; temp=result; result=0; name.value="0"; } function onbutton_equal() { var name=document.getElementByIdx_x("show"); point=false; //重置 multiple=0.1; //重置 switch (sort) { case 1:result=result+temp; break; case 2:result=temp-result; break; case 3:result=temp*result; break; case 4:result=temp/result; break; } sort=0; //重置 temp=result; result=0; name.value=String(temp); } function onbutton_clear() //重置為初始狀態(tài) { result=0; point=false; multiple=0.1; //初始化小數(shù)點后的倍率 sort=0; //標(biāo)記加減乘除 temp=0; //記錄上一輪結(jié)果 var name=document.getElementByIdx_x("show"); name.value="0"; } </script></head> <body> <table align="center"> <tr> <td colspan="5"><input type="text" value="0" id="show"></td> </tr> <tr> <td><input type="button" value="7" onclick="onbutton7();"></td> <td><input type="button" value="8" onclick="onbutton8();"></td> <td><input type="button" value="9" onclick="onbutton9();"></td> <td><input type="button" value="/" onclick="onbutton_div();"></td> <td><input type="button" value="<" onclick="onbutton_back();"></td> </tr> <tr> <td><input type="button" value="4" onclick="onbutton4();"></td> <td><input type="button" value="5" onclick="onbutton5();"></td> <td><input type="button" value="6" onclick="onbutton6();"></td> <td><input type="button" value="*" onclick="onbutton_mult();"></td> <td><input type="button" value="C" onclick="onbutton_clear();"></td> </tr> <tr> <td><input type="button" value="1" onclick="onbutton1();"></td> <td><input type="button" value="2" onclick="onbutton2();"></td> <td><input type="button" value="3" onclick="onbutton3();"></td> <td><input type="button" value="-" onclick="onbutton_minus();"></td> <td rowspan="2"><input type="button" value="=" style="width:25px;height:57px;" onclick="onbutton_equal();"></td> </tr> <tr> <td colspan="2"><input type="button" value="0" style="width:57px;height:25px;" onclick="onbutton0();"></td> <td><input type="button" value="." onclick="onbutton_point();"></td> <td><input type="button" value="+" onclick="onbutton_plus();"></td> </tr> </table></body></html>新聞熱點
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