| Class definitions have the general form
class <name>(<superclass name>):
<class variables>
<class methods>
<instance methods>
The parenthesized superclass name is omitted for basic classes. Items within the class definition can appear in any order.
Example:
class Student:
NUM_GRADES = 5
def __init__(self, name):
self.name = name
self.grades = []
for i in range(Student.NUM_GRADES):
self.grades.append(0)
def getName(self): return self.name
def getGrade(self, i):
return self.grades[i – 1]
def setGrade(self, i, newGrade):
self.grades[i – 1] = newGrade
def __str__(self):
“””Format: Name on the first line
and all grades on the second line,
separated by spaces.
“””
result = self.name + ‘\n’
result += ”.join(map(str, self.grades))
return result
Usage:
s = Student(‘Mary’)
for i in range(1, Student.NUM_GRADES + 1)
s.setGrade(i, 100)
print s |
Class definitions have the general form
<visbility modifier> class <name> extends <superclass name>
implements <list of names>{
<class variables>
<class methods>
<instance variables>
<instance methods>
<inner classes>
}
Classes that do not explicitly extend another class extend the Object class by default. A class may implement zero or more interfaces.
Example:
public class Student{
public static final int NUM_GRADES = 5;
private String name;
private int[] grades;
public Student(String name){
this.name = name;
this.grades = new int[NUM_GRADES];
}
public String getName(){
return this.name;
}
public int getGrade(int i){
return this.grades[i – 1];
}
public void setGrade(int i, int newGrade){
this.grades[i – 1] = newGrade;
}
public String toString(){
/*
Format: Name on the first line
and all grades on the second line,
separated by spaces.
*/
String result = this.name + ‘\n’;
for (String grade : this.grades)
result += grade + ‘ ‘;
return result;
}
}
Usage:
Student s = new Student(“Mary”);
for (int i = 1; i <= Student.NUM_GRADES; i++)
s.setGrade(i, 100);
System.out.println(s);
|