MacBook delete button showing unusual characters

SmNahiduzzaman wrote:

\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\ if i press the delete button then its showing like this.please advise how to solve the issue...

Try an external keyboard. If it works correctly, the internal one may be damaged.

If this is about the iPhone keyboard, did you try to turn the display in landscape mode and tap again on the delete key?

Is the key for backslash directly in front of your Delete key?