Neil coding之路

     const inventors = [
      { first: 'Albert', last: 'Einstein', year: 1879, passed: 1955 },
      { first: 'Isaac', last: 'Newton', year: 1643, passed: 1727 },
      { first: 'Galileo', last: 'Galilei', year: 1564, passed: 1642 },
      { first: 'Marie', last: 'Curie', year: 1867, passed: 1934 },
      { first: 'Johannes', last: 'Kepler', year: 1571, passed: 1630 },
      { first: 'Nicolaus', last: 'Copernicus', year: 1473, passed: 1543 },
      { first: 'Max', last: 'Planck', year: 1858, passed: 1947 },
      { first: 'Katherine', last: 'Blodgett', year: 1898, passed: 1979 },
      { first: 'Ada', last: 'Lovelace', year: 1815, passed: 1852 },
      { first: 'Sarah E.', last: 'Goode', year: 1855, passed: 1905 },
      { first: 'Lise', last: 'Meitner', year: 1878, passed: 1968 },
      { first: 'Hanna', last: 'Hammarström', year: 1829, passed: 1909 }
    ];
    const people = ['Beck, Glenn', 'Becker, Carl', 'Beckett, Samuel', 'Beddoes, Mick', 'Beecher, Henry', 'Beethoven, Ludwig', 'Begin, Menachem', 'Belloc, Hilaire', 'Bellow, Saul', 'Benchley, Robert', 'Benenson, Peter', 'Ben-Gurion, David', 'Benjamin, Walter', 'Benn, Tony', 'Bennington, Chester', 'Benson, Leana', 'Bent, Silas', 'Bentsen, Lloyd', 'Berger, Ric', 'Bergman, Ingmar', 'Berio, Luciano', 'Berle, Milton', 'Berlin, Irving', 'Berne, Eric', 'Bernhard, Sandra', 'Berra, Yogi', 'Berry, Halle', 'Berry, Wendell', 'Bethea, Erin', 'Bevan, Aneurin', 'Bevel, Ken', 'Biden, Joseph', 'Bierce, Ambrose', 'Biko, Steve', 'Billings, Josh', 'Biondo, Frank', 'Birrell, Augustine', 'Black, Elk', 'Blair, Robert', 'Blair, Tony', 'Blake, William'];

    // Array.prototype.filter()
    // 1. Filter the list of inventors for those who were born in the 1500's
        const born=inventors.filter(obj=>obj.year>=1500&&obj.year<1600);
        console.table(born);
    // Array.prototype.map()
    // 2. Give us an array of the inventors' first and last names
       const names=inventors.map(obj=>obj.first+" "+obj.last);
       console.log(names);
    // Array.prototype.sort()
    // 3. Sort the inventors by birthdate, oldest to youngest
       const young=inventors.sort((a,b)=>b.year-a.year);
       console.table(young);
    // Array.prototype.reduce()
    // 4. How many years did all the inventors live?
        const text=inventors.map((obj=>obj.passed-obj.year));
        const year=text.reduce((acc,cur)=>acc+cur,0);
        console.log(year);
    // 5. Sort the inventors by years lived
        const lived=inventors.sort((a,b)=>(b.passed-b.year)-(a.passed-a.year));
         console.table(lived);
    // 7. sort Exercise
    // Sort the people alphabetically by last name
     console.log(people.sort((a,b)=>a.localeCompare(b)));
    // 8. Reduce Exercise
    // Sum up the instances of each of these
    const data = ['car', 'car', 'truck', 'truck', 'bike', 'walk', 'car', 'van', 'bike', 'walk', 'car', 'van', 'car', 'truck' ];
    var obj=data.reduce((sum,cur)=>{if(!sum[cur])sum[cur]=0;sum[cur]++;return sum},{});
    console.log(obj);