1 (one)
The absolute value of the complex number z = r · eiφ with r = 1 is
|eiφ| = 1
Explanation
You can show the unit complex numbers in a circle the complex plane. All points on this circle group conform to Euler's formula
and therefor they give the points shown in the Argand diagram.
Substitution of φ in the formula gives the values
→ → → →
As the only real values are 1 and –1, the absolute value is 1.