The notes E F and B C are always one semitone apart (one fret). All other notes are a tone apart (2 frets). Sharps (#) and flats (b) are found between the notes that are a tone apart.
This scale is called the chromatic scale and contains all the #’s and b’s possible. C sharp (C#) has the same position on the fretboard as D flat (Db). They are the same note but can have different names depending upon what key you are playing in. The same applies to D#/Eb , F#/Gb, G# /Ab, A#/Bb. These are called enharmonic notes. Written here are all the notes on the bass including these sharps and flats.
Also notice that:
These note positions are important to remember because they are the basis for tuning your bass to itself. (See Tuning the Bass to Itself)