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CSS Base

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Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

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Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

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HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

            
              // Double exclamation to boolean a value
var foo = 0;
console.log(!!foo);

// Converting arguments object to an array
(function() {
	console.log(arguments instanceof Array);
	var args1 = Array.prototype.slice.call(arguments);
	var args2 = [].slice.call(arguments);
	// or ES6
	const args3 = Array.from(arguments);
	const args4 = [...arguments];
	console.log(args1 instanceof Array, args2 instanceof Array, args3 instanceof Array, args4 instanceof Array);
})();

// Assigning default values
function bar(opts) {
  var msg = opts.message || 'Hello world!';
  console.log(msg);
};
bar({message:''});

// Checking value by two conditions without conditionals
function isAdult(age) {
   return age && age > 17 ;
};
console.log(isAdult(18));

// Converting to array
var value = "Test";
var totallyArray = [].concat(value);
console.log(totallyArray);

// Converting strings to numbers
var newNumber = +'12.2';
console.log(typeof(newNumber));

// Use tilde to check if element is present in array
// (tilde returns -(N+1))
if (~[1, 2, 3].indexOf(2)) console.log('includes');

// Writing multi-line strings with .join()
var multiStr = [
  "This is the first line",
  "This is the second line",
  "This is more..."
].join("\n");
console.log(multiStr);

// Looping through an array without condition parameter (if order is not important)
var arr = ["one", "two", "three"]
for (var i = arr.length; i--;) {
  console.log(arr[i]);
}

// Use setTimeout with 0 to schedule a function to run after the current event loop tick
setTimeout(function() {
  console.log("log message from next tick");
}, 0);
console.log("Hello World 1")
console.log("Hello World 2")

// Use void 0 instead of undefined
console.log(void 0);
            
          
!
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