• [x] 类型转换：补完函数 convertStringToNumber， convertNumberToString

    1. 老师提供的参考待补齐版本：

    1. <script>
    2.   function convertStringToNumber(string, x) {
    3.       if (arguments.length < 2)
    4.           x = 10;
    5.       var chars = string.split('');
    6.       var number = 0;
    7.       var i = 0;
    8.       while (i < chars.length && chars[i] != '.') {
    9.           number = number * x;
    10.           number += chars[i].codePointAt(0) - '0'.codePointAt(0);
    11.           i++;
    12.       }
    13.       if (chars[i] === '.') {
    14.           i++;
    15.       }
    16.       var fraction = 1;
    18.       while (i < chars.length) {
    19.           fraction = fraction / x;
    20.           number += (chars[i].codePointAt(0) - '0'.codePointAt(0)) * fraction;
    21.           i++;
    22.       }
    23.       return number;
    24.   }
    25.   convertStringToNumber("100");
    27.   function convertNumberToString(number, x) {
    28.       var integer = Math.floor(number);
    29.       var fraction = number - integer;
    30.       var string = '';
    31.       while (integer > 0) {
    32.           string = String(integer % x) + string;
    33.           integer = Math.floor(integer / x);
    34.       }
    35.       return string;
    36.   }
    37.   convertNumberToString(100.1, 10);
    38. </script>

2. 需求分析

待补充的功能如下：

2.1 字符串转数值

需要加入指数相关的程序， W03-H1 类型转换 - 图1

2.2 数值转字符串功能

对于16进制的情况，取余函数结果大于等于10的时候需要转换成ABCDEF

3. 字符串转数值（含指数部分）

  1.   function convertStringToNumber(string){
  2.     // 判断字符串合法性
  3.     r1 = /^(0b|0B)(0|1)+$/
  4.     r2 = /^(0o|0O)[0-7]+$/
  5.     r3 = /^(0x|0X)[0-9a-fA-F]+$/
  6.     r4 = /(^(0|([1-9]\d*)).(\d*)?((e|E){1}(\+|\-)?\d+)?$)|(^.\d+((e|E){1}(\+|\-)?\d+)?$)|(^(0|([1-9]\d*))((e|E){1}(\+|\-)?\d+)?$)/
  8.     if (r1.exec(string) !== null) {
  9.       return convertS2N(string.slice(2),2)
  10.     }
  11.     else if (r2.exec(string) !== null) {
  12.       return convertS2N(string.slice(2),8)
  13.     }
  14.     else if (r3.exec(string) !== null) {
  15.       return convertS2N(string.slice(2),16)
  16.     }
  17.     else if (r4.exec(string) !== null) {
  18.       // 判断字符串中是否含有指数部分
  19.       if (string.includes('e')) {
  20.         // 拆分实数部分和指数部分
  21.         chars=string.split('e')
  22.         console.log(chars)
  23.         num = convertS2N(chars[0])
  24.         exponent = 1 
  25.         // 判断指数部分符号位
  26.         if (chars[1][0]==='-') {
  27.           exponent = -1 
  28.           chars[1] = chars[1].slice(1)
  29.         }
  30.         // 指数部分无意义的“+”和前置的0
  31.         if (chars[1][0]==='+') {
  32.           chars[1]= chars[1].slice(1)
  33.         }
  34.         exponent = exponent * convertS2N(chars[1])
  35.         num=num*Math.pow(10,exponent)
  36.         return num 
  37.       }
  38.       else if (string.includes('E')) {
  39.         // 拆分实数部分和指数部分
  40.         chars=string.split('E')
  41.         console.log(chars)
  42.         num = convertS2N(chars[0])
  43.         exponent = 1 
  44.         // 判断指数部分符号位
  45.         if (chars[1][0]==='-') {
  46.           exponent = -1 
  47.           chars[1] = chars[1].slice(1)
  48.         }
  49.         // 指数部分无意义的“+”和前置的0
  50.         if (chars[1][0]==='+') {
  51.           chars[1]= chars[1].slice(1)
  52.         }
  53.         exponent = exponent * convertS2N(chars[1])
  55.         num=num*Math.pow(10,exponent);
  56.         return num;
  57.       }
  58.       else {
  59.         return convertS2N(string)
  60.       }
  61.     }
  62.     else {
  63.       return null
  64.     }
  65.   }
  67.   // 老师提供的部分 修改一下名字
  68.   function convertS2N(string, x) {
  69.     if (arguments.length < 2)
  70.       x = 10;
  71.     var chars = string.split('');
  72.     var number = 0;
  73.     var i = 0;
  74.     while (i < chars.length && chars[i] != '.') {
  75.       number = number * x;
  76.       number += chars[i].codePointAt(0) - '0'.codePointAt(0);
  77.       i++;
  78.     }
  79.     if (chars[i] === '.') {
  80.       i++;
  81.     }
  82.     var fraction = 1;
  84.     while (i < chars.length) {
  85.       fraction = fraction / x;
  86.       number += (chars[i].codePointAt(0) - '0'.codePointAt(0)) * fraction;
  87.       i++;
  88.     }
  89.     return number;
  90.   }
  92.   // 测试
  93.   console.log(convertStringToNumber("0B1010")); 
  94.   console.log(convertStringToNumber("0b1110"));
  95.   console.log(convertStringToNumber("0O1053"));
  96.   console.log(convertStringToNumber("0o1760"));
  97.   console.log(convertStringToNumber("0x1ab8"));
  98.   console.log(convertStringToNumber("0X1AB0"));
  99.   console.log(convertStringToNumber("132"));
  100.   console.log(convertStringToNumber("100.123"));
  101.   console.log(convertStringToNumber(".164"));
  102.   console.log(convertStringToNumber("132E12"));
  103.   console.log(convertStringToNumber("100.123e-23"));
  104.   console.log(convertStringToNumber(".164e+2"));
  105.   console.log(convertStringToNumber(".164e+02"));
  106.   console.log(convertStringToNumber(".164e002"));
  107.   console.log(convertStringToNumber(".164E00000000"));
  108.   console.log(convertStringToNumber("0xER2312"));

4. 数值转字符串

  1.     function convertNumberToString(number, x) {
  2.         if (arguments.length < 2)
  3.             x = 10;
  4.         var integer = Math.floor(number);
  5.         var fraction = number - integer;
  6.         var string = '';
  7.         while (integer > 0) {
  8.             if (integer % x < 10 ) {
  9.                 string = String(integer % x) + string;
  10.             }
  11.             else if (integer % x === 10 ) {
  12.                 string = "A" + string;
  13.             }
  14.             else if (integer % x === 11 ) {
  15.                 string = "B" + string;
  16.             }
  17.             else if (integer % x === 12 ) {
  18.                 string = "C" + string;
  19.             }
  20.             else if (integer % x === 13 ) {
  21.                 string = "D" + string;
  22.             }
  23.             else if (integer % x === 14 ) {
  24.                 string = "E" + string;
  25.             }
  26.             else if (integer % x === 15 ) {
  27.                 string = "F" + string;
  28.             }
  30.             integer = Math.floor(integer / x);
  31.         }
  32.         return string;
  33.     }