freecodecamp训练

简介

介绍下freecodecamp组织，以”帮助人们免费学习编程”为使命，创建了大量免费的编程教程，包括交互式课程、视频课程、文章等。看完HTML、CSS、JS理论知识后，我已经等不及想在freecodecamp实战啦！每次课题挑战成功，我会截图保存下来，总结自己遇到难题

如果题目太难或不理解，抄作业总会吧？

第一篇 响应式网页设计认证

1.Tribute Page

这是一个链接，点我查看致敬页

2.Survey Form

这是一个链接，点我查看调查表单

3.Product Landing Page

这是一个链接，点我查看产品登入页

4.Technical Documentation Page

这是一个链接，点我查看技术文档页

5.Personal Portfolio

这是一个链接，点我查看个人作品集展示页

第二篇 JavaScript算法和数据结构

1. 回文检查器

function palindrome(str) {
  // 除了英文数字，过滤其他符号
  let a = str.match(/[a-zA-Z0-9]/g).join('').toLowerCase();

  // 字符串取反
  let b = a.split('').reverse().join('');

  // 判断回文字符串
  return a === b;
}

palindrome("eye");

2. 罗马数字转换器

function convertToRoman(num) {
    const map = new Map([['M',1000],['CM',900],['D',500],['CD',400],['C',100],['XC',90],['L',50],['XL',40],['X',10],['IX',9],['V',5],['IV',4],['I',1]]);
    let result = '';
    for (let v of map) {
        const temp = parseInt(num/v[1],0);
        if (temp > 0) {
            for (let i = 0; i < temp; ++i) {
                result += v[0]
            }
        }
        num = num % v[1]
    }
    return result
}

convertToRoman(36);

3. 凯撒密码

function rot13(str) {
  // 翻译表
  let ObjRot13 = {
    A: 'N',
    B: 'O',
    C: 'P',
    D: 'Q',
    E: 'R',
    F: 'S',
    G: 'T',
    H: 'U',
    I: 'V',
    J: 'W',
    K: 'X',
    L: 'Y',
    M: 'Z',
    N: 'A',
    O: 'B',
    P: 'C',
    Q: 'D',
    R: 'E',
    S: 'F',
    T: 'G',
    U: 'H',
    V: 'I',
    W: 'J',
    X: 'K',
    Y: 'L',
    Z: 'M',
  };
  // 用数组接收翻译内容
  let translate = [];
  for (let i = 0; i < str.length; i++) {
    if (/[A-Z]/g.test(str[i])) {
      translate.push(ObjRot13[str[i]]);
    } else {
      translate.push(str[i]);
    }
  }
  // 返回翻译数组转成字符串
  return translate.join('');
}


rot13("SERR PBQR PNZC");

4. 电话号码检查器

function telephoneCheck(str) {
    let reg = /^1\s?\(\d{3}\).?\d{3}.?\d{4}|^1\s\d{3}[\(|-]\d{3}[-]\d{4}|^\d{10}$|\d{3}\s\d{3}\s\d{4}|^\(\d{3}\)\d{3}-\d{4}|^\d{3}-\d{3}-\d{4}$/
    const bol = reg.test(str);
    return bol
}

telephoneCheck("555-555-5555");

5. 计算找零

function checkCashRegister(price, cash, cid) {
  let change = [];

  let unit = {
    "ONE HUNDRED": 100,
    TWENTY: 20,
    TEN: 10,
    FIVE: 5,
    ONE: 1,
    QUARTER: 0.25,
    DIME: 0.1,
    NICKEL: 0.05,
    PENNY: 0.01,
  }

  let cidUnitCount = getUnitCount(cid, unit);
  let remain = cash - price, isSuit = true;
  for (let key in unit) {
    if (unit[key] <= remain) {
      const unitPrice = unit[key];
      const unitTotalCount = cidUnitCount[key];
      let curTotalPrice = 0, curCount = 0;
      while (curTotalPrice < remain && curCount < unitTotalCount) {
        curCount++;
        curTotalPrice = curCount * unitPrice;
      }
      if (curTotalPrice > remain) {
        curCount--;
        curTotalPrice = curCount * unitPrice;
      }
      if (curCount !== 0) {
        change.push([key,curTotalPrice ]);
        remain = (remain - curTotalPrice).toFixed(2);
      }
      if (curCount !== unitTotalCount) {
        isSuit = false;
      }
    }
  }
  let result;
  if (remain == 0) {
    if (isSuit) {
      result = { status: "CLOSED", change: cid };
    } else {
      result = { status: "OPEN", change: change };
    }
  } else {
    result = { status: "INSUFFICIENT_FUNDS", change: [] };
  }
  return result;
}

function getUnitCount(arr, unit) {
  let result = {};
  arr.forEach(item => {
    const [key, value] = item;
    result[key] = Math.round(value / unit[key]);
  })
  return result;
}

checkCashRegister(19.5, 20, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]]);

checkCashRegister(3.26, 100, [["PENNY", 1.01], ["NICKEL", 2.05], ["DIME", 3.1], ["QUARTER", 4.25], ["ONE", 90], ["FIVE", 55], ["TEN", 20], ["TWENTY", 60], ["ONE HUNDRED", 100]])

checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])

checkCashRegister(19.5, 20, [["PENNY", 0.01], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 1], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])

checkCashRegister(19.5, 20, [["PENNY", 0.5], ["NICKEL", 0], ["DIME", 0], ["QUARTER", 0], ["ONE", 0], ["FIVE", 0], ["TEN", 0], ["TWENTY", 0], ["ONE HUNDRED", 0]])