JSFiddle - React, Tailwind, and code Playground

JavaScript

var data = [
  {'k':'v'},
  {'k2':'v2'},
  {'k3':'v3'}
];

var flatData = {'k':'v', 'k2':'v2', 'k3':'v3'};

function Flatten(source) {
    if (!source || !source.length || source.length === 0) {
        return source;
    }
    var output = {};
    for (var i = 0; i < source.length; i++) {
        for (prop in source[i]) {
            if (source[i].hasOwnProperty(prop)) {
                output[prop] = source[i][prop];
            }
        }
    }
    return output;
}

console.log(data);
console.log(flatData);
console.log(Flatten(data));
console.log(Flatten(flatData));