精品成品网站源码,网页设计模板大全,动漫网站设计源代码,校园门户网站 建设本方法的思路为#xff1a; 一#xff1a;检查了输入的合法性#xff08;非空#xff0c;无非法字符#xff09; 二#xff1a;检查输入是否可以进行简单计算#xff08;一个数为 0#xff0c;1#xff0c;1#xff0c;-1#xff09; 三#xff1a;去掉输入最前面可…本方法的思路为 一检查了输入的合法性非空无非法字符 二检查输入是否可以进行简单计算一个数为 011-1 三去掉输入最前面可能有的正负符号并判断输出的正负 四将输入的值分成4位一截分的长度太短性能太差长度太长精度容易降低 五遍历相乘得到最终数组这里用了递归 六遍历最终数组拼接最终的数不建议用join,因为数组中的元素可能小于四位拼接时会丢失0 七将正负符号与最终的数拼接输出 代码如下 !DOCTYPE html
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headtitle/titlescript typetext/javascriptvar num1 ;var num2 ;var finallyArr;/** 有两个用字符表示的非常大的大整数算出他们的乘积也是用字符串表示不能用系统自带的大整数类型。* 输入例子72106547548473106236 982161082972751393* 输出例子7082024482963453804084865646610598674870820244829634538040848656466105986748*/function getResult(){finallyArr new Array();num1 document.getElementById(num1).value;num2 document.getElementById(num2).value; if(!checkNum(num1)){alert(输入:num1 不合法);return;}if(!checkNum(num2)){alert(输入:num2 不合法);return;}//特殊情况的简单算法if(doSimpleWay()){return;}//获取最终值的正负符号var symbol initSymbol();//将输入的值分成4位一小截的数组var numArr1 getNumArr(num1,new Array());var numArr2 getNumArr(num2,new Array());//遍历相乘相加得到最终的数组for(var i 0; i numArr1.length; i){for(var j 0; j numArr2.length; j){updateFinallyArr(i j , numArr1[i] * numArr2[j]); }}//倒序遍历数组获取最终结果var resultStr finallyArr.pop();for(var i finallyArr.length; i 0; i--){if(finallyArr[i] 1000){resultStr finallyArr[i];}else if(finallyArr[i] 1000){resultStr 0 finallyArr[i];}else if(finallyArr[i] 100){resultStr 00 finallyArr[i];}else if(finallyArr[i] 10){resultStr 000 finallyArr[i];}else if(finallyArr[i] 0){resultStr 0000;}}document.getElementById(RESULT).innerText symbol resultStr;}/*** 根据数值以及数值的位置更新最终的数组*/function updateFinallyArr(i , num){var old finallyArr[i];if(old){num num old;}if(num 9999){finallyArr[i] num % 10000;updateFinallyArr(i 1 , Math.floor(num/10000) );}else{finallyArr[i] num;}}/*** 处理输入字符串的正负号并判断最终值的正负号*/function initSymbol(){if(num1.substring(0,1) -){num1 num1.substring(1,num1.length); if(num2.substring(0,1) -){num2 num2.substring(1,num2.length);}else if(num2.substring(0,1) ){num2 num2.substring(1,num2.length);return -;}else{return -;}}else if(num1.substring(0,1) ){num1 num1.substring(1,num1.length); if(num2.substring(0,1) -){num2 num2.substring(1,num2.length);return -;}else if(num2.substring(0,1) ){num2 num2.substring(1,num2.length); }}return ;}/*** 特殊情况的简单算法*/function doSimpleWay(){if(num1 0 || num2 0){document.getElementById(RESULT).innerText 0;return true;}else if(num1 1 || num1 1){document.getElementById(RESULT).innerText num2;return true;}else if(num2 1 || num2 1){document.getElementById(RESULT).innerText num1;return true;}else if(num1 -1){if(num2.substring(0,1) - ){document.getElementById(RESULT).innerText num2.substring(1,num2.length);}else if(num2.substring(0,1) ){document.getElementById(RESULT).innerText - num2.substring(1,num2.length);}else{document.getElementById(RESULT).innerText - num2;}return true;}else if(num2 -1){if(num1.substring(0,1) - ){document.getElementById(RESULT).innerText num1.substring(1,num1.length);}else if(num1.substring(0,1) ){document.getElementById(RESULT).innerText - num1.substring(1,num1.length);}else{document.getElementById(RESULT).innerText - num1;}return true;}return false;}/*** 获取4位一小截的数组*/function getNumArr(num,arr){var len num.length;if(len 4){arr.push(num.substring(len-4,len) * 1);num num.substring(0,len-4);return getNumArr(num,arr);}else{arr.push(num * 1);return arr;}}/*** 检查输入数字的正确性非空、无不合法字符*/function checkNum(num){if(!num){return false;}var str num.replace(/[0-9]/g,);if(str || (str - num.substring(0,1) - num.length 1) || (str num.substring(0,1) num.length 1) ){if(num.length 1000){return false;}return true;}else{return false;}}/script
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bodynum1:input typetext idnum1 name value7210654754847310623672106547548473106236721065475484731062367210654754847310623672106547548473106236 stylewidth:80%/brnum2:input typetext idnum2 name value9821610829727513939821610829727513939821610829727513939821610829727513939821610829727513939821610829 stylewidth:80%/brinput typebutton idnum2 value计算 onclickgetResult()/brtextarea id RESULT rows5 stylewidth:80%/textarea
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/html 转载于:https://www.cnblogs.com/ttjsndx/p/8549659.html
