does anyone know why my todo list is printing out numbers?

    var dailyToDo=[];
    var completed=[];
    console.log("Add a single item to the to do list or add multiple ones seperated by commas. Type 'exit' to exit, 'remove' to remove an item, 'complete' to add an item to the completed list' and 'show completed' to show completed list ");

    while(true){
        var userInput= prompt('+').split(',');
        for(item in userInput){
            if(item[0]==' '){
                newItem= item.substring(1,item.length);
                item=newItem
            }
        }
        dailyToDo+= userInput;
        if(userInput.includes('exit')){
            break;
        }
        else if(userInput.includes('remove')){
            var removeInput=prompt('what idea do you want removed? ');
            var removedItem=dailyToDo.indexOf(removeInput);
            dailyToDo.splice(removedItem,1);
            continue 
        }
        else if(userInput.includes('complete')){
            var completeInput= prompt('What task did you complete? ');
            var completeIndex= dailyToDo.indexOf(completeInput);
            completed+=dailyToDo.splice(completeIndex,1);
            continue            
        }
        else if(userInput.includes('show completed')){
            for(item in completed){
                console.log(item);
            }
            continue
        }
        else{
            for(item in dailyToDo){
            console.log(item)
            }
        }