function typeChecker(_input){
  if([undefined, null, NaN].includes(_input)){
    return _input;
  }else if(_input === 'true' || _input === 'false'){
  	 return "Boolean";
  }else if(new RegExp(".*[a-zA-Z]+.*").test(_input) || _input === ''){
     return typeof _input;
  }else{
    return Number.isInteger(+_input) ? 'integer' : 'flaot';
  }
}

console.log(typeChecker(undefined));