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Issue 296 fixed: 6.1 comments to code #304

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Merged
pearcej merged 1 commit into from
Jul 31, 2026
Merged

Issue 296 fixed: 6.1 comments to code #304

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64 changes: 42 additions & 22 deletions source/ch6_definingclasses.ptx
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Original file line number Diff line number Diff line change
Expand Up @@ -76,37 +76,54 @@
"""
self.num = num
self.den = den
def __repr__(self):
if self.num > self.den:
retWhole = int(self.num / self.den)
retNum = self.num - (retWhole * self.den)
def __repr__(self):
"""
:return: a string representation of the fraction
"""
if self.num > self.den:
retWhole = int(self.num / self.den) # find the whole number part
retNum = self.num - (retWhole * self.den) # find the numerator part
return str(retWhole) + " " + str(retNum) + "/" + str(self.den)
else:
return str(self.num) + "/" + str(self.den)
def show(self):
"""
:return: print the fraction
"""
print(self.num, "/", self.den)
def __add__(self, other):
"""
:param other: the fraction to add
:return: the sum of the two fractions
"""
# convert to a fraction
other = self.toFract(other)
newnum = self.num * other.den + self.den * other.num
newden = self.den * other.den
newnum = self.num * other.den + self.den * other.num # find the new numerator
newden = self.den * other.den # find the new denominator
common = gcd(newnum, newden)
return Fraction(int(newnum / common), int(newden / common))
__radd__ = __add__
__radd__ = __add__ # allow the fraction to be added to a number
def __lt__(self, other):
"""
:param other: the fraction to compare
:return: whether the fraction is less than the other
"""
num1 = self.num * other.den
num2 = self.den * other.num
return num1 < num2
def toFract(self, n):
"""
:param n: the number to convert to a fraction
:return: the fraction representation of the number
"""
if isinstance(n, int):
other = Fraction(n, 1)
elif isinstance(n, float):
wholePart = int(n)
fracPart = n - wholePart
# convert to 100ths???
fracNum = int(fracPart * 100)
newNum = wholePart * 100 + fracNum
other = Fraction(newNum, 100)
fracPart = n - wholePart
fracNum = int(fracPart * 100) # convert to 100ths
newNum = wholePart * 100 + fracNum # combine the whole and fractional parts
other = Fraction(newNum, 100)
elif isinstance(n, Fraction):
other = n
else:
Expand All @@ -115,9 +132,12 @@
return other
def gcd(m, n):
"""
A helper function for Fraction
A helper function for Fraction.
:param m: the first number
:param n: the second number
:return: the greatest common divisor
"""
while m % n != 0:
while m % n != 0: # keep going until the gcd is found
oldm = m
oldn = n
m = oldn
Expand All @@ -140,8 +160,8 @@
<listing xml:id="java-fraction-class-start">
<program interactive="activecode" language="java">
<code>
public class Fraction {
private Integer numerator;
public class Fraction {
private Integer numerator; // notice the private modifier
private Integer denominator;
}
</code>
Expand All @@ -157,8 +177,8 @@
<listing xml:id="java-private">
<program interactive="activecode" language="java">
<code>
Fraction f = new Fraction(1,2);
Integer y = f.numerator * 10;
Fraction f = new Fraction(1,2);
Integer y = f.numerator * 10; // trying to access the numerator
</code>
</program>
</listing>
Expand All @@ -174,16 +194,16 @@
<listing xml:id="java-getter-and-setter">
<program interactive="activecode" language="java">
<code>
public Integer getNumerator() {
public Integer getNumerator() { // getter method
return numerator;
}
public void setNumerator(Integer numerator) {
public void setNumerator(Integer numerator) { // setter method
this.numerator = numerator;
}
public Integer getDenominator() {
public Integer getDenominator() { // getter method
return denominator;
}
public void setDenominator(Integer denominator) {
public void setDenominator(Integer denominator) { // setter method
this.denominator = denominator;
}
</code>
Expand Down