Javascript: 101 Week 2 Track 2

167-exercise41.js

var cat = {}; // a 'set' of names
cat['Red Lion'] = {'colour': 'grey', 'size': 46}; // a name is added to this set
cat['Doctor Hobbles'] = {'colour': 'white', 'size': 15};
cat['Little Iroquois'] = {'colour': 'yellow', 'size': 30};
delete cat['Doctor Hobbles']; // a name is removed from this set
if ('Red Lion' in cat) { // check whether a name occurs in this set.
    alert('you have "Red Lion" cat.');
}

167-exercise410.js

function range(num, start) {
    var list = [];
    if (arguments.length < 2) {
        for (var i = 0; i <= num; i++) {
            list[i] = i;
        }
    } else {
        for (var x = 0, y = num; y <= start; x++, y++) {
            list[x] = y;
        }
    }
    return list;
}
document.write(range(5)); // 0, 1, 2, 3, 4, 5
document.write(range(2, 5)); // 2, 3, 4, 5

167-exercise411.js

function range(num, start) {
    var list = [];
    if (arguments.length < 2) {
        for (var i = 0; i <= num; i++) {
            list[i] = i;
        }
    } else {
        for (var x = 0, y = num; y <= start; x++, y++) {
            list[x] = y;
        }
    }
    return list;
}
function sum(numbers) {
    result = 0;
    for (var i = 0; i < numbers.length; i++) {
        result += numbers[i];
    }
    return result;
}
document.write(sum(range(1, 10))); // 55

167-exercise42.js

function range(num) {
    var list = [];
    for (var i = 0; i <= num; i++) {
        list[i] = i;
    }
    return list;
}
document.write(range(5));

167-exercise43.js

var sentence = ["We are", "family"];
sentence.join(" ").split(" ");

167-exercise44.js

function startsWith (firstString, secondString) {
    var result = false;
    firstLength = firstString.length;
    secondLength = secondString.length;
    if (secondLength > firstLength)
        return result;

    if (firstString.slice(0, secondLength) == secondString)
        result = true;
    return result;
}
document.write(startsWith("oranges", "orange")); // true
document.write(startsWith("peach", "orange"));   // false
document.write(startsWith("peaches", "grape"));  // false

167-exercise45.js

function catNames(paragraph) {
    var result = [];
    var colon = paragraph.indexOf(":");
    allCat = paragraph.slice(colon + 1);
    names = allCat.split(",");
    for (var i = 0; i < names.length; i++) {
        var catName = names[i].split("");
        var startName;
        var endName;
        // Trims whitespace from the left side of the string.
        for (var j = 0; j < catName.length; j++) {
            startName = j;
            if (catName[j] != " ")
                break;
        }
        // Trims whitespace from the right side of the string.
        for (var k = catName.length - 1; k > -1; k--) {
            endName = k;
            if (catName[k] != " ")
                break;
        }
        result.push(names[i].slice(startName, endName+1));
    }
    return result;
}
var paragraph = "born 05/04/2006 (mother Lady Penelope): Red Lion, Doctor" +
  "Hobbles the 3rd, Little Iroquois";
document.write(catNames(paragraph));

167-exercise46.js

function extractDate(paragraph) {
    var colon = paragraph.indexOf(":");
    var space = paragraph.indexOf(" ");
    var allDate = paragraph.slice(space + 1, colon);
    var dates = allDate.split("/");
    var day = dates[0];
    var month = dates[1];
    var year = dates[2];
    var result = new Date(year, month-1, day);
    return result;
}
var paragraph = "died 27/04/2006: Black Leclère";
document.write(extractDate(paragraph));

167-exercise47.js

function between(paragraph, firstPattern, secondPattern) {
    var start = paragraph.indexOf(firstPattern) + firstPattern.length;
    var end = paragraph.indexOf(secondPattern, start);
    return paragraph.slice(start, end);
}
document.write(between("born 15/11/2003 (mother Spot): White Fang",
  "(mother ", ")")); // "Spot"
document.write(between("bu ] boo [ bah ] gzz", "[ ", " ]")); // "bah"

167-exercise48.js

function formatDate(date) {
    var month = date.getMonth() + 1;
    var day = date.getDate();
  return ((day < 10)? ("0" + day) : day) +
         "/" + ((month < 10)? ("0" + month) : month) +
         "/" + date.getFullYear();
}

document.write(formatDate(new Date(2010, 11, 25))); // "25/12/2010"
document.write(formatDate(new Date(2011, 1, 4))); // "04/02/2011"

167-exercise49.js

function oldestCat(cats) {
    var cat;
    var oldest;
    for (var name in cats) {
        if (!("death" in cats[name]) && !oldest || (oldest > cats[name].birth))
        {
            oldest = cats[name].birth;
            cat = cats[name].name;
        }
    }
  return cat;
}
var cats = {"Spot": {name:"Spot", birth: new Date(1997, 2, 5),
            mother: "Yellow"},
            "White": {name:"White", birth: new Date(1998, 7, 4),
            mother: "Zebra"},
            "Grey": {name:"Grey", birth: new Date(1996, 6, 3),
            mother: "Kitten"}};
document.write(oldestCat(cats)); // "Grey"