The JavaScript native .some() method does exactly what you're looking for:

function isBiggerThan10(element, index, array) {
  return element > 10;
}

[2, 5, 8, 1, 4].some(isBiggerThan10);  // false
[12, 5, 8, 1, 4].some(isBiggerThan10); // true

I'm a little late to the party, but...

[].some(Boolean)

I believe this to be the cleanest and readable option:

var empty = [];
empty.some(x => x); //returns false

var a = [];
a.length > 0

I would just check the length. You could potentially wrap it in a helper method if you like.

JavaScript arrays can be "empty", in a sense, even if the length of the array is non-zero. For example:

var empty = new Array(10);
var howMany = empty.reduce(function(count, e) { return count + 1; }, 0);

The variable "howMany" will be set to 0, even though the array was initialized to have a length of 10.

Thus because many of the Array iteration functions only pay attention to elements of the array that have actually been assigned values, you can use something like this call to .some() to see if an array has anything actually in it:

var hasSome = empty.some(function(e) { return true; });

The callback passed to .some() will return true whenever it's called, so if the iteration mechanism finds an element of the array that's worthy of inspection, the result will be true.

Just use Array.length:

var arr = [];

if (arr.length)
   console.log('not empty');
else
   console.log('empty');

See MDN

If you really want to got nuts, add a new method to the prototype:

if (!('empty' in Array.prototype)) {
  Array.prototype.empty = function () {
    return this.length === 0;
  };
}

[1, 2].empty() // false
[].empty() // true

DEMO

What you want is .empty not .empty() to fully mimics Ruby :

     Object.defineProperty( Array.prototype, 'empty', {
           get: function ( ) { return this.length===0 }
      } );    

then

[].empty //true
[3,2,8].empty //false

For any , see my answer here

Array has a length property :

[].length // 0
[0].length // 1
[4, 8, 15, 16, 23, 42].length // 6

polyfill* :

Array.prototype.any=function(){
    return (this.some)?this.some(...arguments):this.filter(...arguments).reduce((a,b)=> a || b)
};

If you want to call it as Ruby , that it means .any not .any(), use :

Object.defineProperty( Array.prototype, 'any', {
  get: function ( ) { return (this.some)?this.some(function(e){return e}):this.filter(function(e){return e}).reduce((a,b)=> a || b) }
} ); 

__

`* : https://en.wikipedia.org/wiki/Polyfill

As someone suggested in one of the comments, checking if an array contains any elements can be done with a simple use of some.

let hasItems = array.some(x => true);
let isEmpty = !array.some(x => true);

// test data
const data = [[1,2,3,4,5,6],[], [1,7,10]];

// function to check if any condition is satisfied
const any = (condition) => (data) => data.some(condition);

// function to check if empty
const empty = (data) => !data?.length

data.forEach((f) => {
    console.log(`any ${JSON.stringify(f)} -> ${any(x => x %7 == 0)(f)}`);
    console.log(`empty ${JSON.stringify(f)} -> ${empty(f)}`);
});

Just use ternary operator

let myArray = []
myArray && myArray.length ? console.log(true) : console.log(false)