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计算器练习

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8 table {9 margin: 15px auto;10 font-size: 22px;11 border: 5px outset orange;12

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15 #tab-1,16 #tab-2,17 #tab-3{18 border: 3px outset rgba(15, 10, 10, 0.3);19 }20

21 input {22 outline: none;23 box-shadow: 5px 5px 2px rgba(100, 100, 100, 0.8) inset;24 }25

26 #txtnum {27 text-align: right;28 height: 50px;29 width: 100%;30 background: #fff;31 font-size: 22px;32 }33

34 td {35 padding: 5px;36 background: #ccc;37

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40 [type=button] {41 width: 60px;42 height: 40px;43 border-radius: 5px;44 background: #fff;45 box-shadow: 5px 3px 2px rgba(100, 100, 100, 0.6) inset;46 }47

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141 //operator 运算符

142 var Boo = false; //判断是否按下计算符号的布尔变量；

143 var result = 0; //存储计算数据的变量

144 var ope; //存储计算符号的变量

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146 function$(x) {147 returndocument.getElementById(x);148 }149

150 functiondecimal() {151 var txt = $(‘txtnum‘);152 if(Boo) {153 txt.value = ‘0.‘; //若接受过运算符，文本框清零

154 } else{155 if (txt.value.indexOf(‘.‘) == -1) { //判断数值中是否已经有小数点

156 txt.value += ‘.‘; //若没有则加上

157 }158 }159 Boo = false; //若接受过运算符，文本框不能清零

160 }161 //indexOf() 方法可返回某个指定的字符串值在字符串中首次出现的位置。

162 //如果要检索的字符串值没有出现，则该方法返回 -1。

163

164 functionnum(Num) {165 var txt = $(‘txtnum‘);166 if(Boo) {167 txt.value =Num;168 Boo = false;169 } else{170 if (txt.value == ‘0‘) {171 txt.value =Num;172 } else{173 txt.value +=Num;174 }175 }176 }177

178 functioncompute(op) {179 var onum = $(‘txtnum‘).value;180 if (onum == ‘‘) { onum = 0; }181 Boo = true;182 switch(ope) {183 case ‘+‘:184 result += parseFloat(onum); break;185 case ‘-‘:186 result -= parseFloat(onum); break;187 case ‘*‘:188 result *= parseFloat(onum); break;189 case ‘/‘:190 result /= parseFloat(onum); break;

191 case ‘=‘:192 result = parseFloat(onum); break;193 case ‘%‘:194 result %= onum; break;195 //{result%=onum;break;}break;

196 case ‘x^y‘:197 result = Math.pow(result, onum); break;198 //{result=Math.pow(result,onum);break;}break;

199 default: result = parseFloat(onum); break;200 }201 $(‘txtnum‘).value =result;202 ope =op;203

204 }205

206 functionmath(op) {207 var onum = $(‘txtnum‘).value;208 if (onum == ‘‘) { alert(‘数据不能为空‘); };209 Boo = true;210 with(Math) {211 switch(op) {212 case ‘sin‘: result = sin(onum); break;213 case ‘cos‘: result = cos(onum); break;214 case ‘tan‘: result = tan(onum); break;215 case ‘asin‘: result = asin(onum); break;216 case ‘acos‘: result = acos(onum); break;217 case ‘atan‘: result = atan(onum); break;218 case ‘PI‘: result = PI; break;219 case ‘1/x‘: result = 1 / onum; break;220 case ‘e‘: result = E; break;221 case ‘lnx‘: result = log(onum); break;222 case ‘lgx‘: result = log(onum) / log(10); break;223

224 case ‘i‘: result = floor(onum); break;225

226 case ‘sqrt‘: result = jc(onum); break;227 default: result = parseFloat(onum); break;228 }229 }230 $(‘txtnum‘).value =result;231 }232

233 functionjc(a) {234 returnMath.sqrt(a);235 }236

237 functionreverse() {238 var Num1 = $(‘txtnum‘).value;239 if (Num1 == ‘‘) {240 alert(‘数据不能为空‘);241 } else{242 $(‘txtnum‘).value *= -1;243 }244

245 }246

247 functionbackspace() {248 var txt = $(‘txtnum‘);249 txt.value = txt.value.substring(0, txt.value.length - 1);250 if (txt.value == ‘‘) { txt.value = 0; }251 }252

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