CODEWITHSUNDEEP
javascripthtmlcss
alex472
alex472

Reputation: 25

Getting random values from objects inside an array by clicking a button

I need to a get a random string from the objects inside an array when you click the button. But for some reason my code is not executing.

var quotes = [{
    quote: "Quote1",
    source: "Source1"
  },
  {
    quote: "Quote2",
    source: "Source2"
  },
  {
    quote: "Quote3",
    source: "Source3"
  },
  {
    quote: "Quote4",
    source: "Source4"
  },
  {
    quote: "Quote5",
    source: "Source5"
  }
];

function getRandomquote() {
  var randomindex = Math.floor(Math.random() * (quotes.length));
  var quotesarr = quotes[randomindex];
  var objquote = quotesarr.quote;
  var objsource = quotesarr.source;

  document.getElementById("quote").innerHTML = objquote;
  document.getElementById("source").innerHTML = objsource;
}

function printQuote() {
  document.getElementById("loadQuote").onclick = getRandomquote;
}
printQuote();
<div class="container">
  <div id="quote-box">
    <p class="quote"> hello</p>
    <p class="source"> hello</p>
  </div>
  <button id="loadQuote" onclick="printQuote();">Show another quote</button>

I am getting this error message:

Uncaught TypeError: Cannot set property 'innerHTML' of null at HTMLButtonElement.getRandomquote (randomtest1.js:27)

Update after answers below

I changed getElementById to getElementsByClassName, and now there are no error messages.

But when I click the button, it does not change the elements. I believe I have made a mistake on the printQuote function. I cannot figure it out.

Upvotes: 0

Views: 125

Answers (5)

Jijo Cleetus
Jijo Cleetus

Reputation: 2847

Please find the working code below. i have removed unwanted functions.

html 

<div id="quote-box">
  <p class="quote">hello</p>
  <p class="source">hello</p>
</div>
<button id="loadQuote" onclick="getRandomquote();">Show another quote</button>

js

var quotes=[
{quote:"Quote1", source:"Source1"},
{quote:"Quote2", source:"Source2"},
{quote:"Quote3", source:"Source3"},
{quote:"Quote4", source:"Source4"},
{quote:"Quote5", source:"Source5"}
        ];
getRandomquote=function(){

var randomindex=Math.floor(Math.random()*(quotes.length));  
var quotesarr=quotes[randomindex];
document.getElementsByClassName("quote")[0].innerHTML=quotesarr.quote;
document.getElementsByClassName("source")[0].innerHTML=quotesarr.source;
}

Upvotes: 1

alex472
alex472

Reputation: 25

I changed getElementById to getElementsByClassName, and now there are no error messages.

But when I click the button, it does not change the elements. I believe I have made a mistake on the printQuote function. I cannot figure it out.

Upvotes: 0

G0dsquad
G0dsquad

Reputation: 4435

You can't use getElementById to retrieve an element by its class. You'll need to specify an id or use getElementsByClassName- https://developer.mozilla.org/en/docs/Web/API/Document/getElementsByClassName

var els = document.getElementsByClassName('test')
console.log(els.length)
<div class="test"></div>

In your example:

<p class="quote" id="quote"> hello</p>
<p class="source" id="source"> hello</p>

Upvotes: 1

Sumeet kumar
Sumeet kumar

Reputation: 49

you have not set id in your p tag ...please set id='quote' and it should start working.

Upvotes: 0

DomeTune
DomeTune

Reputation: 1421

You'll need to add the ids to the elements as below. Or use getElementsByClassName() or use querySelector(".quote").

var objquote = "Hello";
var objsource = "World";
document.getElementById("quote").innerHTML=objquote;
document.getElementById("source").innerHTML=objsource;
<div id="quote-box">
  <p id="quote" class="quote"> hello</p>
  <p id="source" class="source"> hello</p>
</div>

Upvotes: 1

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