Question: What is the difference caused by using “nope” instead of ”no”?

Is it used because “nope” sounds better and not straight like “no”? In some situations, it feels like *nope* is better to use than *no* even though it adds 2 more characters. What is the reason why many use it?

Answer: 
From [here](https://english.stackexchange.com/a/59658/31820), they have no difference in meaning; but *nope* is more informal, only used in a sense of opposite to *yes* (or *yup*). Also, *nope* is not used often in writing.

You wouldn't say "there were nope errors", for example.
"Nope" is informal. You wouldn't usually want to use it, for example, answering questions for a job interview, but it would be an appropriate answer to a friend's question "Have you seen that movie yet?"