JSFiddle - React, Tailwind, and code Playground

JavaScript

var objectValue = {variableToChange: 5},
    numberValue = 5;

function valueChanger(changedVariable){
    if(typeof(changedVariable)=='object'){
        changedVariable.variableToChange = 10;
    } else {
        changedVariable = 10;
    }
}


document.write("<b>BEFORE Any Changes</b><br />");
document.write("Value of 'variableToChange' in objectValue: <b>" + objectValue.variableToChange + "</b><br />");
document.write("Value of 'numberValue': <b>" + numberValue  + "</b><br />");

document.write("<b>AFTER Any Changes</b> <i>Function 'valueChanger' makes the value 10</i><br />");
valueChanger(objectValue.variableToChange);
document.write("Value of 'variableToChange' in objectValue (passing only the attibute): <b>" + objectValue.variableToChange + "</b><br />");
valueChanger(objectValue);
document.write("Value of 'variableToChange' in objectValue (passing the whole object): <b>" + objectValue.variableToChange + "</b><br />");
valueChanger(numberValue);
document.write("Value of 'numberValue': <b>" + numberValue  + "</b><br />");