向类的每个元素添加随机字体

Question

Been trying to make it so that each div with the class .book gets allocated a random font from an array. This is my code so far

var fonts = ['Gloria Hallelujah', 'Sedgwick Ave', 'Gochi Hand', 'Patrick Hand', 'Kalam', 'Rock Salt', 'Neucha', 'Caveat Brush', 'Schoolbell'];
var randomfont = fonts[Math.floor(Math.random() * fonts.length)];
$(".book").style.fontFamily = randomfont; 

The error I am getting is: Uncaught TypeError: Cannot set property 'fontFamily' of undefined

Anyone know what I am doing wrong?

Answer 1

$(".book") returns a jquery array. eg to set the first you would use:

$(".book")[0].style.fontFamily = 

You need to loop through $(".book") to get the DOM elements:

$(".book").each(function() {
    var randomfont = fonts[Math.floor(Math.random() * fonts.length)];
    this.style.fontFamily = randomfont; 
});

(unless you meant to set them all to the same font, in which case set randomfont outside the loop).

Answer 2

That's because you are trying to set the fontFamily directly on the jQuery object instead of the DOM element.

Either use jQuery's css method or use get / array selector to retrieve the DOM element.

On the other hand you want to do that on each element, so you need to use each like this:

 //const fonts = ['Gloria Hallelujah', 'Sedgwick Ave', 'Gochi Hand', 'Patrick Hand', 'Kalam', 'Rock Salt', 'Neucha', 'Caveat Brush', 'Schoolbell']; const fonts = ['Helvetica', 'Arial', 'Verdana', 'Courier', 'Courier New']; $('.book').each(function(item) { const randomfont = fonts[Math.floor(Math.random() * fonts.length)]; this.style.fontFamily = randomfont; }); 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <div class="book">Test 1</div> <div class="book">Test 2</div> <div class="book">Test 3</div> <div class="book">Test 4</div> <div class="book">Test 5</div> <div class="book">Test 6</div> 

Answer 3

hope this will help. just call the id using the document.getElementById('') and then set the font value.

var fonts = ['Impact,Charcoal,sans-serif', 'Sedgwick Ave', ' Helvetica', 'Patrick Hand', 'Kalam', 'Rock Salt', 'Neucha', 'Caveat Brush', 'Schoolbell'];
var randomfont = fonts[Math.floor(Math.random() * fonts.length)];
alert(randomfont);
var val=document.getElementById("book").style.fontFamily = randomfont;