I am new to JS and have created this original problem from CodeAcademy which works. Now I wanted to put my flock of sheep into an object and access it using my sheepCounter function. I am new to accessing key/values from an object and am stuck on what I am doing wrong. Thanks in advance!
Original Code
var sheepCounter = function (numSheep, monthNumber, monthsToPrint) {
for (monthNumber = monthNumber; monthNumber <= monthsToPrint; monthNumber++) {
numSheep *= 4;
console.log("There will be " + numSheep + " sheep after " + monthNumber + " month(s)!");
}
return numSheep;
}
New Code:
var flock = {
sheep: 4,
month: 1,
totalMonths: 12
};
var sheepCounter = function (counter) {
for (counter[month] = counter[month]; counter[month] <= counter[totalMonths]; counter[month]++) {
numSheep *= 4;
console.log("There will be " + counter[sheep] + " sheep after " + counter[month] + " month(s)!");
}
return counter[sheep];
}
Found the error in your solution:
var sheepCounter = function (counter) {
for (counter['month'] = counter['month']; counter['month'] <= counter['totalMonths']; counter['month']++) {
counter['sheep'] *= 4;
console.log("There will be " + counter['sheep'] + " sheep after " + counter['month'] + " month(s)!");
}
return counter['sheep'];
}
You can access your Flock Object like so,
alert(flock.sheep); //4
If you have an array in an object, like
names: ['joe','tom','bob'];
You would access that like so,
alert(flock.names[0]); // joe
alert(flock.names[2]); // bob
Related
first and foremost i'm new to javascript and coding. second, i'm coding a book store project with javascript with an alert message that shows each customer's total factor. but the alert message shows the code of my function "printFactor" insted of the string that is made by this function. this is my code:
function Book(name, writer, date, price)
{
this.name = name;
this.writer = writer;
this.date = date;
this.price = price;
}
function Customer(name, gender, turn)
{
this.name = name;
this.gender = gender;
this.turn = turn;
this.numberOfBooks = 0;
this.totalSum = 0;
this.bookList = [new Book("-", "-", "-", 0)];
//Functions.
this.addBook = function (newBook) {
this.numberOfBooks++;
this.bookList.push(newBook);
};
this.printFactor = function () {
var message = "";
if (this.numberOfBooks === 0) {
message = "No Books Has Been Added to Book List!";
return (message);
}
else {
message = this.name + " " + this.gender + " Number of Books: " + this.numberOfBooks + " Customer's Turn: " + this.turn + "\nBooks:\n";
var i;
var newMessage;
for (i = bookList.length - 1; i > 0; i--) {
newMessage = bookList[i].name + " " + bookList[i].writer + " " + bookList[i].date + " " + bookList[i].price.toString() +"\n" ;
message += newMessage;
this.totalSum += bookList[i].price;
this.bookList.pop();
}
newMessage = "Total Sum: " + this.totalSum;
message += newMessage;
return (message);
}
};
}
var book = new Book("Faramarz Bio", "Faramarz Falsafi Nejad", "1377/04/29", 13000);
var faramarz = new Customer("faramarz", "Male", 3);
faramarz.addBook(book);
faramarz.addBook(book);
faramarz.addBook(book);
faramarz.addBook(book);
var m = faramarz.printFactor;
window.alert(m);
You need to invoke the function:
var m = faramarz.printFactor();
As is your variable m contains a reference to the function, but you need to call it to get the result.
var m = faramarz.printFactor();
window.alert(m);
You simply don't call your function, this should work.
var m = faramarz.printFactor()
Beside you reference an unexisting variable 'booklist', that should be "this.booklist"
for (i = this.bookList.length - 1; i > 0; i--) {
newMessage = this.bookList[i].name + " " + this.bookList[i].writer + " " + this.bookList[i].date + " " + this.bookList[i].price.toString() +"\n" ;
You need to actually call the function by adding () to the end, like this:
var m = faramarz.printFactor()
I'm having trouble producing a script to match an object's value in object array based on an object's value in a separate array, and retrieve a separate value from that object.
I have used standard for-loops and the current iteration in jQuery each.
I have also tried setting the if statement to look for the two values as ==, but it always produces non matches (or -1).
Can anyone steer me in the right direction here?
transfers = [
{Package: "1", Origin_Facility = "a"},
{Package: "2", Origin_Facility = "b"}
];
storeData = [
{fromPackage: "1,6,26"}
]
var storeDataEach = function( sx, sxv ) {
var transfersEach = function( sy, syv ) {
if(storeData[sx].fromPackage.indexOf(transfers[sy].Package) > -1){
var facilityStore = transfers[sx].Origin_Facility;
storeData[sx].origin = facilityStore + " + " + transfers[sy].Package + ' + ' + storeData[sx].fromPackage;
return false;
} else {storeData[sx].origin = 'error' + transfers[sy].Package + " + " + storeData[sx].fromPackage;return false;}
};
jQuery.each(transfers, transfersEach);
}
jQuery.each(storeData, storeDataEach);
The main problem is you are returning false from the $.each loop which will stop the iteration
A crude fix is to remove the return from else block
var storeDataEach = function(sx, sxv) {
var transfersEach = function(sy, syv) {
if (storeData[sx].fromPackage.indexOf(transfers[sy].Package) > -1) {
var facilityStore = transfers[sx].Origin_Facility;
storeData[sx].origin = facilityStore + " + " + transfers[sy].Package + ' + ' + storeData[sx].fromPackage;
return false;
} else {
storeData[sx].origin = 'error' + transfers[sy].Package + " + " + storeData[sx].fromPackage;
}
};
jQuery.each(transfers, transfersEach);
}
But this still have problems with the data structure, in your example you have 26 in the fromPackage, now if you have a package value of 2 that also will return a positive result
I have functions in JS that must be hard-coded for some reason. How do I make a function that writes this hard-coded function? Here's my example; assuming obj is a multi-array/JSON object:
function foo2(obj) {
var t = obj["key1"];
t = t["key2"];
return t;
}
function fooN(obj) {
var t = obj["key1"];
t = t["key2"];
...//more goes here
t = t["keyN"];
return t;
}
I know there're easier ways to access multi-array/object, but hard-coded functions like this is by far the fastest, since there is no variable substitution. Thank you.
I don't advocate it, but here's how you could do it:
function defineAccessor(propArray) {
var accessors = propArray.join('.');
return new Function('obj', 'return obj.' + accessors);
}
var x = { key1: { key2: 3 } };
var foo2 = defineAccessor(['key1', 'key2']);
alert(foo2(x)); // alerts 3
Seems like some strange requirements, but a possible solution is to add the functions to window using window['foo' + number].
The main tricky bit in this solution is the closure in the middle that ensures that the correct value of i is used. This is done by calling a function that takes i as an arg and returns a function.
var N = 5;
fooX = function(obj, x) {
var t = obj["key" + 1];
for (var i = 2; i <= x; i++) {
t = t["key" + i];
}
return t;
}
for (var i = 1; i <= N; i++) {
window['foo' + i] = (function(x) {
return function(obj) {
return fooX(obj, x);
}
})(i);
}
var obj = {
key1: {
key2: {
key3: {
key4: {
key5: 5
}
}
}
}
}
var message = "Results:<br>" +
"foo1(obj) = " + foo1(obj) + "<br>" +
"foo2(obj) = " + foo2(obj) + "<br>" +
"foo3(obj) = " + foo3(obj) + "<br>" +
"foo4(obj) = " + foo4(obj) + "<br>" +
"foo5(obj) = " + foo5(obj);
document.body.innerHTML = message;
I'm attempting to create a Choose Your Own Adventure type of game, and I'm currently trying to write a 'battle' script. What I've got so far is:
var name = "Anon";
var health = 100;
var youAttack = [name + " hits the " + opp + " with his sword", name + " uses magic!", name + " is too scared to fight!"];
var youBattle = function() {
var youBattle = youAttack[Math.floor(Math.random() * 3)];
return youBattle;
};
var opp = "Orc";
var oppHealth = 100;
var oppAttack = ["The " + opp + " hits you with his hammer!", "The " + opp + " does nothing!", "The " + opp + " back hands you!"];
var oppBattle = function() {
var oppBattle = oppAttack[Math.floor(Math.random() * 3)];
return oppBattle;
};
oppBattle();
youBattle();
I've done it like this so the opponent and player names can easily be changed.
What I'm struggling to figure out is how I can add / remove health from both the opponent and the player depending what attack is used. Obviously no health would be removed if the opp / player does nothing.
Is there a way I can do this without a bunch of messy if / else statements?
I was hoping for something easy like name + " hits the " + opp + " with his sword" + health = health - 10; but obviously that didn't work.
Thanks in advance!
http://jsbin.com/qerud/3/edit
Hope this isn't too much code:
var Attack = function(hero,opp,damageReceived,damageGiven,message){
this.message = message;
this.damageGiven = damageGiven;
this.damageReceived = damageReceived;
this.opp = opp;
this.hero = hero;
this.attack = function(opp){
this.hero.health -= damageReceived;
this.opp.health -= damageGiven;
return this.message;
};
};
var Character = function(name,health){
this.name = name;
this.health = health;
};
hero = new Character('Anon',100);
orc = new Character('Orc',150);
attack1 = new Attack(hero,orc,5,0,"The " + orc.name + " back hands you!");
attack2 = new Attack(hero,orc,0,0,hero.name + " is too scared to fight!");
attack3 = new Attack(hero,orc,15,0,"The " + orc.name + " hits you with his hammer!");
attack4 = new Attack(hero,orc,0,25,hero.name + " uses magic!");
attacks = [attack1,attack2,attack3,attack4];
while(hero.health > 0 && orc.health > 0){
console.log(attacks[Math.floor(Math.random() * 4)].attack());
console.log('Hero Health: '+ hero.health);
console.log('Orc Health: '+ orc.health);
}
if(hero.health > 0 ){
console.log(hero.name + ' won');
} else {
console.log('The ' + orc.name + ' won');
}
I can tell you first hand that trying to write this type of code uses a lot of if/else and more statements, regardless of what language you're using. You can use an array to hold the values of your attack patterns:
var attackName = ["Punch", "Sword", "Magic"]
var attackDamage = [3, 5, 4]
function youAttack(ATK, PHit) {
if(playerHit) {
playerDamage = ATK + PHit;
oppHealth = oppHealth - playerDamage;
return oppHeath;
} else {
alert("You missed!");
}
}
But, without seeing exactly what you're doing I cannot say how you should do your attacks and damages. I can only assume. You will need a system of evaluating attacks, misses, etc. that does use IF/ELSE Statements at least somewhere.
This is the code that I currently have, one problem that is happening is I cannot use test() because presets[index].name and value are not visible outside of their function scope, how should I declare my array of objects in the global scope in order for me to be able to access these two variables in other functions?
var presets = [];
var index;
function CreatePresetArray(AMib, AVar) {
var parentpresetStringOID = snmp.getOID(AMib, AVar);
var presetStringOID = parentpresetStringOID;
parentpresetStringOID = parentpresetStringOID.substring(0, parentpresetStringOID.length - 2);
log.error("parentpresetStringOID is " + parentpresetStringOID);
var presetswitches = {};
for (var i = 1; i < 41; i++) {
presets.push(presetswitches);
try {
log.error("presetStringOID before getNextVB= " + presetStringOID);
vb = snmp.getNextVB(presetStringOID);
presetStringOID = vb.oid;
log.error("presetStringOID after getnextVB= " + presetStringOID);
var presetStringVal = snmp.get(presetStringOID);
log.error("presetStringVal= " + presetStringVal);
index = i - 1;
presets[index].name = presetStringOID;
presets[index].value = presetStringVal;
log.error("preset array's OID at position [" + index + "] is" + presets[index].name + " and the value stored is " + presets[index].value);
//log.error("presets Array value ["+index+"] = "+presets[index].configs);
if (presetStringOID.indexOf(parentpresetStringOID) != 0) {
break;
}
} catch (ie) {
log.error("couldn't load preset array " + index);
};
};
}
CreatePresetArray(presetMib, "presetString");
function test() {
for (i = 1; i < 41; i++) {
log.error("test" + presets[index].name + " " + presets[index].value);
};
}
test();
The for loop in your function test iterates over i but uses index inside the loop. Perhaps you meant to use
for (i = 0; i < 40; i++) { // 1 lower as you were using `index = i - 1` before
log.error("test" + presets[i].name + " " + presets[i].value);
}
Re-wrote your code. I don't think I made that much by way of change. If this doesn't clear up your problem, consider: Is the catch happening each iteration? Is the problem actually coming from a different method which is only visible here? Also, consider logging the whole presets Array when debugging to see what it looks like.
var presets = [];
function CreatePresetArray(AMib, AVar) {
var parentPresetOID, presetOID, presetValue, preset, vb, i;
parentPresetOID = snmp.getOID(AMib, AVar);
presetOID = parentPresetOID; // initial
parentPresetOID = parentPresetOID.substring(0, parentPresetOID.length - 2);
log.error("parentPresetOID is " + parentPresetOID);
presets = []; // empty array in case not already empty
for (i = 0; i < 40; ++i) {
try {
preset = {}; // new object
// new presetOID
vb = snmp.getNextVB(presetOID);
presetOID = vb.oid;
log.error("presetOID after getnextVB= " + presetOID);
// new value
presetValue = snmp.get(presetOID);
log.error("presetValue= " + presetValue);
// append data to object
preset.name = presetOID;
preset.value = presetValue;
// append object to array
presets.push(preset);
// more logging
log.error(
"preset array's OID at position [" + i + "]" +
" is" + presets[i].name + " and " +
"the value stored is " + presets[i].value
);
if (presetOID.indexOf(parentPresetOID) !== 0) {
break;
}
} catch (ie) {
log.error("couldn't load preset array " + i);
if (presets.length !== i + 1) { // enter dummy for failed item
presets.push(null);
}
}
}
}
Two options come to mind immediately:
you could pass the preset array as a argument to test().
You could put both CreatePresetArray() and test() inside a wrapper function and declare preset array at the top of your wrapper. That would give them both access to the variable.
It's generally considered Bad Form to declare globals if it can be avoided. Pollutes the namespace.