JSFiddle - React, Tailwind, and code Playground

HTML

<!-- PLEASE OPEN YOUR JAVASCRIPT CONSOLE! -->
<!--Organize Your Console Logging With a Custom debug() Function -->
<!-- blog.kevinchisholm.com -->
<!-- Example # 3A -->

JavaScript

var
//show debug messages
debugMode = false,

myDebug = function(msg,callback){
    //if app not in debug mode, exit immediately
    if(!debugMode || !console){return};

    //console.log the message
    if(msg && (typeof msg === 'string')){console.log(msg)};

    //execute the callback if one was passed-in
    if(callback && (callback instanceof Function)){
      callback();
    };
},

//objects to merge  
obj1 = {
    name: 'alfred e newman',
    phone: '212-555-1212'
},
obj2 = {
    account: '010203',
    address: '404 Mad Ave. - MadCity NY, 12345'
},

//array for testing
myArr = ['monday','tuesday','wednesday','thursday','friday'],

//combines two objects
combineObjects = function(objA,objB){
    var
    newObj = {},
    merge = function(baseObj,addObj){
        for(var prop in addObj){
            if(addObj.hasOwnProperty(prop)){
                baseObj[prop] = addObj[prop];
            };
        };
    };

    merge(newObj,objA);
    merge(newObj,objB);

    //debug message
    myDebug('the new combined object is: ',function(){
        console.dir(newObj);
    });

    return newObj;
},

//converts an array of strings to upper-case
arrayToUpper = function(arr){
    //code that does something with arr

    for(var i = 0; i < arr.length; i++){
        arr[i] = arr[i].toUpperCase();

        //debug message
        myDebug( ('the new string for element # ' + (i + 1) + ' is: ' + arr[i]) );
    };
}

//call the functions
var foo = combineObjects(obj1,obj2)
arrayToUpper(myArr);

//added for proof-of-concept
console.dir(foo);
console.dir(myArr);