random_wild_pokemon.md

Chapter 5: Create a Random Wild Pokemon

In the previous chapter, we initialized our contract with 20 pokemon names. Now, it's the time we battle ⚔️

Funtion with multiple return values

A function can also return multiple return values like the following:

struct Student:
    name: String[32]
    age: uint256

# a mapping between roll number and
# student details
studentList: HashMap[uint256, Student]

@external
def getPersonDetails(rollNumber: uint256) -> (String[32], uint256):
    student: Student = self.studentList[rollNumber]
    return student.name, student.age

Put it to the test

1. Create an @external function named battle which has 1 input paramter: pokemon of type Pokemon. It returns 4 parameters: bool, String[32], uint256, uint256.

2. Inside the battle function, create a uint256 variable named randomDNA. Now call the _generateRandomDNA function and assign its output to randomDNA.

3. Inside the battle function, create a String[32] variable named randomName. Now to assign a value to randomName, we have to select a random name from pokemonNames by passing any uint256 from 0 to 19 as key. We can generate a suitable random uint256 by following operation: randomDNA modulus NAME_MODULUS.

4. Inside the battle function, create a uint256 variable randomHP. Set its value equal to randomDNA modulus (%) HP_LIMIT.

** Template **

embedded-code

** Solution **

embedded-code-final

** Previous Chapter Solution **

embedded-code-previous