Search code examples
javascriptarraysreduceenumerable

How to `reduce` over an object?

I wonder how to use some reduce logic over an object rather than an array. Something like iterating over tuples represented by

[ object_property, property_value ]).

I tried some code like

var obj = { foo: 'bar', bar: 'baz' };
Array.prototype.reduce.call(obj, function(prev, val) {
    console.log('new iteration');
    // whatever code ...
    return prev;
}, []);

but it doesn't perform any iteration. I can't understand why.

Maybe because the object properties are not enumerable?

Is there any way to run a reduce function on an object?

Note: There is no specific final purpose; I am exploring what's possible or what might be better patterns.

Solution

  • Array methods like reduce() can only operate on arrays or array-like objects (with length and numeric properties).

    You can call Object.values() to get an array of an object's property values.