Develop Reference

How to make variables optional while concatenation of string?

I am manipulating string to display in UI, Data is being dynamically with below code sometime i don't get header and details so how to make IHeader and IResponse optional for the string concatenation below.
if i dont have IHeader it will break at IHeader.id and throw exception i want to display whatever data is available to render.
main.js
const data = [{
id: "header",
name: "IHeader"
}, {
id: "param",
name: "IParams"
}, {
id: "details",
name: "IResponse"
}]
function buildText(data) {
var IParams;
var IResponse;
var IHeader;
for (var item of data) {
if (item.id === "param") {
IParams = item;
} else if (item.id === "header") {
IHeader = item;
} else if (item.id === "details") {
IResponse = item;
}
}
var text = '';
text += app + '.setConfig({\n' + "env:" + getEnv() + '\n});' + '\n\n';
text += 'let param:' + IParams.name + ' ' + '=' + '' + JSON.stringify(request, null, 4) + ';\n\n';
text += ref + '(' + 'param,(result:' + ' ' + '{' + '\n' + IHeader.id + ':' + IHeader.name + '\n' + IResponse.id + ':' + IResponse.name + '\n' + '})' + ' ' +
' => {\n console.log(result); \n});';
}

1 - You can try to create an object with empty values. That'll prevent the exception.
emptyObject = {id: ""} // more empty keys, if there is
IParam = (item.id === "param") ? item : emptyObject
2 - Or ignore that concatenation of the variable if undefined or null.
if (Iparam) {
// concatenation ..
}

Print out each array value in the iteration, value is undefined

I want to print out the content of the composed array. As you can see I call console.log at the end of the code and every value in the composed array is undefined. But if I call console.log at somewhere else such as if statement, the values are right. Please tell me why, thanks!
$(function() {
var text = $('p').text().split('');
var letter = 0;
var composed = [];
$.each(text, function(index, value) {
if (/\w/.test(value)) { // if the character is alphanumeric
var prev = index - 1;
var next = index + 1;
if (/\w/.test(text[prev])) {
composed[letter] = composed[letter] + value;
if (!/\w/.test(text[next])) {
console.log('composed[' + letter + '] = ' + composed[letter]);
letter++;
}
} else {
composed[letter] = value;
if (!/\w/.test(text[next])) {
console.log('composed[' + letter + '] = ' + composed[letter]);
letter++;
}
}
} else {
composed[letter] = value;
console.log('composed[' + letter + '] = ' + composed[letter]);
letter++;
}
console.log('composed[' + letter + '] = ' + composed[letter]); // undefined
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p>Test both Chinese中文 ,alphbets and numbers.</p>

console.log('composed[' + letter + '] = ' + composed[letter - 1]);
this gives correct value

your composed[letter] is "undefined" because previous state is letter++;

Perhaps you meant this?
var letter = 0;
var composed = [];
function addLetter(letter, value) {
// your could ignore white-space and punctuation there
if (composed[letter]) composed[letter] += value
else composed[letter] = value;
}
$(function() {
var text = $('p').text().split('');
$.each(text, function(index, value) {
if (/\w/.test(value)) { // if the character is alphanumeric
var prev = index - 1;
var next = index + 1;
if (/\w/.test(text[prev])) {
addLetter(letter, value)
if (!/\w/.test(text[next])) {
letter++;
}
} else {
addLetter(letter,value);
if (!/\w/.test(text[next])) {
letter++;
}
}
} else {
addLetter(letter, value)
letter++;
}
});
console.log(composed)
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<p>Test both Chinese中文 ,alphabets and numbers 1234.</p>

Just add a check for spaces. to ensure the we are not manipulating spaces.
**if (/\w/.test(text[prev] && composed[letter]!=" "))**
--
$(function() {
var text = $('p').text().split('');
var letter = 0;
var composed = [];
$.each(text, function(index, value) {
if (/\w/.test(value)) { // if the character is alphanumeric
var prev = index - 1;
var next = index + 1;
if (/\w/.test(text[prev] && composed[letter]!=" ")) {
composed[letter] = composed[letter] + value;
if (!/\w/.test(text[next])) {
console.log('composed[' + letter + '] = ' + composed[letter]);
letter++;
}
} else {
composed[letter] = value;
if (!/\w/.test(text[next]) && composed[letter]!=" ") {
console.log('composed[' + letter + '] = ' + composed[letter]);
letter++;
}
}
} else {
composed[letter] = value;
console.log('composed[' + letter + '] = ' + composed[letter]);
letter++;
}
console.log('composed[' + letter + '] = ' + composed[letter]); // undefined
});
});

Trying to grab a innerhtml from within a innerhtml

So i've recently ran into issues with trying to move specific pieces of a <p> </p> called result. as such i thought hey! wouldn't be easier to break each part inside of result down into another <p>!? well it works lol however trying to grab that inner <p> that in this cause we'll call vault is being difficult. I've tried several methods but cant seem to grab it's value from outside in a document.getElementByID....here's the code below for the html.
document.getElementById("result").innerHTML = Monster + "<p id='vault'> || HP: " + HP + "</p> || Defense: " + Def + " || Attack: " + ATK + " || Can it Dodge/Block: " + DB + " || Can it retaliate: " + RET + " || Initative: " + INT + " || Exp: " + MEXP + " <input type='submit' class='new' onclick='Combat(" + loop + ")' value='FIGHT!'></input>" + "<br><br>" + A;
}
then the script that eventually calls it
function Combat(id){
document.getElementById("vault").innerHTML = id;
document.getElementById("C").value = id
}
So what i'm trying is change id "C" to ID"VAULT" inside of id ("result").
any ideas on why i can't grab vault?

What you want would be easier with Object-oriented JavaScript.
Usually when coding JavaScript you want to be as independent of the DOM (HTML) as possible.
Consider the following example:
/**
* Monster
*/
var Monster = (function() {
function Monster(HP, DEF, ATK, DB, RET, INT, MEXP) {
if (HP === void 0) {
HP = 100;
}
if (DEF === void 0) {
DEF = 10;
}
if (ATK === void 0) {
ATK = 100;
}
if (DB === void 0) {
DB = 10;
}
if (RET === void 0) {
RET = true;
}
if (INT === void 0) {
INT = 100;
}
if (MEXP === void 0) {
MEXP = 100;
}
this.HP = HP;
this.DEF = DEF;
this.ATK = ATK;
this.DB = DB;
this.RET = RET;
this.INT = INT;
this.MEXP = MEXP;
}
/**
* getHTML
*/
Monster.prototype.getHTML = function() {
return "HP: " + this.HP + " || Defense: " + this.DEF + " || Attack: " + this.ATK + " || Can it Dodge/Block: " + this.DB + " || Can it retaliate: " + this.RET + " || Initative: " + this.INT + " || Exp: " + this.MEXP;
};
/**
* attacked
*/
Monster.prototype.attacked = function(damage) {
if (damage === void 0) {
damage = 0;
}
//check defences
if (damage > this.DEF + this.DB) {
//take damage
this.HP -= (damage - this.DEF + this.DB);
}
if (this.HP < 0) {
//Return true if it slew the monster
return true;
} else {
//Return false if the monster survived
return false;
}
};
return Monster;
}());
/**
* Area
*/
var Area = (function() {
function Area(name) {
if (name === void 0) {
name = "Vault";
}
this.name = name;
this.monsters = [];
}
/**
* addMonster
*/
Area.prototype.addMonster = function(monster) {
this.monsters.push(monster);
return this;
};
/**
* attackVault
*/
Area.prototype.assault = function(damage) {
if (damage === void 0) {
damage = 0;
}
//If no monster
if (this.monsters.length < 1) {
alert("You have cleared this vault");
return true;
} else {
//If monsters exists, attack the first
var monsterKilled = this.monsters[0].attacked(damage);
//If the monster was killed
if (monsterKilled) {
//remove monster
this.monsters.splice(0, 1);
//Alert the player
alert("Well done hero!\nOnly " + (this.monsters.length) + " remaining!");
}
}
//Return maybe monsters left?
return this.monsters.length < 1;
};
return Area;
}());
////GRAP HTML ELEMENT
var output = document.getElementById("current-monster");
////RUNNING YOUR GAME
//Build and populate world
var vault = new Area();
vault
.addMonster(new Monster())
.addMonster(new Monster());
//INTERACTION
alert("Start");
//Hit the vault till it is empty
while (vault.assault(45) != true) {
output.innerHTML = vault.monsters[0].getHTML();
alert("Attack!");
}
output.innerHTML = "Victory!";
<h1 id="title">Monster Game!</h1>
<h2 id="current-monster"></h2>
See how i can easily access the data though JavaScript?
When coding a JavaScript game, it makes sense to keep important data and structures in your JavaScript.

Ok so i added the bit - ADyson suggested...
document.getElementById("result").innerHTML = Monster + "<p id='vault(" + loop + ")'> || HP: " + HP + "</p>" + " || Defense: " + Def + " || Attack: " + ATK + " || Can it Dodge/Block: " + DB + " || Can it retaliate: " + RET + " || Initative: " + INT + " || Exp: " + MEXP + " <input type='submit' class='new' onclick='Combat(" + loop + ")' value='FIGHT!'></input>" + "<br><br>" + A;
}
}
}
function Chest(id){
window.open('LootGen.html', '_blank');
}
function Combat(id){
var id = document.getElementById("vault" + id).innerHTML;
document.getElementById("C").value = id;
submit();
}
However now when i run it on the " ).innerHTML;" i'm getting a
MonsterGen.html:426 Uncaught TypeError: Cannot read property
'innerHTML' of nullCombat # MonsterGen.html:426onclick #
MonsterGen.html:1

Ok I found out exactly was was going wrong; it was the naming convention in the <P>.
Originally it was id='vault(" + loop + ")'... this would make it vault(1) etc.... however the getElement was getting it by this call ("vault" + id) so it would call vault1....thus two separate id's entirely....that's why it was returning null.
So I removed the () in the equation and now everything is working beautifully.

InnerHTML Append Item instead of Replace

I'm trying to make a palindrome script and it's actually "working".
I want to make a improvement. I want the input value append on my "output" div.
here are my fiddle http://jsfiddle.net/vitorboccio/8yh1u0t7/
any hints ? I dont want to use Jquery ! Thanks!
(function () {
"use strict";
var output = document.getElementById("output"),
statusLine = document.getElementById("status"),
phrase = document.getElementById('phrase'),
testButton = document.getElementById("testButton"),
//palindromeText = document.getElementById("palindrome"),
characterCheck = document.getElementById("characterCheck"),
ignoreSpecialCharacters = false,
ignoreSpaces = false;
function setMessage(palindrome) {
if (palindrome) {
output.innerHTML = phrase.value + ' ' + "é palindroma";
} else {
output.innerHTML = phrase.value + ' ' + "não é a palindroma";
}
}
function checkForPalindrome(string) {
var palindrome = true,
right = string.length - 1,
left = 0;
if (!string || string.length < 1) {
// 0 characters
return false;
}
while (left < right && palindrome) {
palindrome = string.charAt(left) === string.charAt(right);
left++;
right--;
}
return palindrome;
}
function executeTest() {
var string = phrase.value,
cleanString;
cleanString = string;
if (ignoreSpaces) {
//ignores whitespaces only;
cleanString = string.replace(/\s+/g, '');
}
if (ignoreSpecialCharacters) {
//ignores punctuation and white space (controversial).
cleanString = string.replace(/[A-Z0-9]/ig, '');
}
if (checkForPalindrome(cleanString)) {
setMessage(true);
palindromeText.innerHTML = '"' + string + '"';
} else {
setMessage(false);
}
}
function executeOnEnter(e) {
if (e.keyCode === 13) {
executeTest();
// phrase.blur();
}
}
//resets the form to state 1
function resetForm() {
output.innerHTML = "";
//statusLine.innerHTML = "Waiting";
statusLine.style.color = "green";
phrase.value = "";
}
function charIgnoreChanged(e) {
ignoreSpecialCharacters = e.target.checked;
}
function spaceIgnoreChanged(e) {
ignoreSpaces = e.target.checked;
}
phrase.addEventListener('keydown', executeOnEnter);
testButton.addEventListener('click', executeTest);
characterCheck.addEventListener('change', charIgnoreChanged);
spaceCheck.addEventListener('change', spaceIgnoreChanged);
}());

You just need to modify setMessage
function setMessage(palindrome) {
if (palindrome) {
output.innerHTML += phrase.value + ' ' + "é palindroma<br />";
} else {
output.innerHTML += phrase.value + ' ' + "não é a palindroma<br />";
}
// for user convenience, clear the textbox and give it focus
phrase.value = '';
phrase.focus();
}
Fiddle

You can append to the div by keeping the original innerHTML like this:
output.innerHTML = output.innerHTML + "<br />" + phrase.value + ' ' + "é palindroma";
or shorter:
output.innerHTML += "<br />" + phrase.value + ' ' + "é palindroma";

JSON parsing in javascript

I'm trying to parse JSON in JavaScript. If my JSON data looks like below, I want to iterate through all the JSON elements that start with "custom" and not with any other string. How do I do this?
{
"fields": {
"custom12": {
value: "dsada"
},
"custom45": {
value: "adsadad"
},
"test12": {
value: "12323"
}
}
}​

var newObject = {}, key;
for(key in data.fields){
if(key.search(/custom/) > -1){
newObject[key] = data.fields[key];
}
}
console.log(newObject);

The following iterates the properties of the fields object and checks whether the property's name contains custom:
var data = yourObjectLiteral, i, current;
for(i in data.fields) {
if(i.indexOf('custom') > -1) {
current = data.fields[i];
// ... your logic ...
}
}

With the json string you provided I'd do it as such:
<script src="json2.js"></script>
<script>
var raw = '{'
+ ' "fields": {'
+ ' "custom12": {'
+ ' "value": "dsada"'
+ ' },'
+ ' "custom45": {'
+ ' "value": "adsadad"'
+ ' },'
+ ' "test12": {'
+ ' "value": "12323"'
+ ' }'
+ ' }'
+ '}';
var data = JSON.parse(raw);
var fields = data.fields;
var message = '';
for (var key in fields) {
if (key.indexOf('custom') === 0) {
message += key + ': ' + fields[key].value + '\n';
}
}
alert(message);
</script>
But, if you can rewrite the incomming message a little it will look simpler.
<script src="json2.js"></script>
<script>
var raw = '{'
+ ' "custom12": "dsada",'
+ ' "custom45": "adsadad",'
+ ' "test12": "12323"'
+ '}';
var fields = JSON.parse(raw);
var message = '';
for (var key in fields) {
if (key.indexOf('custom') === 0) {
message += key + ': ' + fields[key] + '\n';
}
}
alert(message);
</script>