Test if something is not undefined in JavaScript

response[0] is not defined, check if it is defined and then check for its property title.

if(typeof response[0] !== 'undefined' && typeof response[0].title !== 'undefined'){
    //Do something
}

Just check if response[0] is undefined:

if(response[0] !== undefined) { ... }

If you still need to explicitly check the title, do so after the initial check:

if(response[0] !== undefined && response[0].title !== undefined){ ... }