コード

Array.from({length:5},(_,i) =>
    console.log(i)
);

Array.from({length: 5}, function(_, i) {
    console.log(i);
});

$.each([...Array(3).keys()], (i) => 
    console.log(i)
);

$.each([...Array(3).keys()], (i) => {
    console.log(i);
});

$.each([1,2,3,4,5],(_,i) =>
    console.log(i)
);

[...Array(5).keys()].forEach(i => 
	console.log(i)
);

const num = 15;

console.log([...Array(num).keys()]);

// １から始めたいなら
console.log([...Array(num).keys()].map(n => ++n));

$.each([...Array(fields.length).keys()], function(_,i) {
    console.log(i);
})

結果