Promise.reduce skips first array element.

http://jsfiddle.net/RichAyotte/t0rjhrab/

var pets = ['cat', 'dog', 'bird'];
Promise.reduce(pets, function(_, p) {
    console.log(p);   
});

Log

dog
bird

[cantremember]

that is expected behavior. your 0th argument is being used as the initial value for the reduce

http://jsfiddle.net/cantremember/766up1an/

var pets = ['cat', 'dog', 'bird'];
Promise.reduce(pets, function(_, p) {
    console.log(p);
    return _ + ',' + p;
}).then(function(_) {
    console.log('=', _); // => 'cat,dog,bird'
});

whereas pass a 3rd argument, such as 'mouse' to Promise#reduce and you’ll see each element of your Array being visited

[cantremember]

thanks, good to know. i must have overlooked that