A stylus comprises a first shell, a second shell, a first slide enabling member. The first shell has a first hole defined therethough. The second shell is slidably accommodated in the first hole of the first shell. The first slide enabling member couples the second shell to the first shell such that the second shell slides relative to the first shell from a retracted configuration to an extending configuration. The first slide enabling member includes a first pin and a first track that engages the first pin, the second shell slides relative to the first shell along the first pin.