# Chapter 6: Decision and control statements¶

### Example 6.1, Page number: 114¶

In :
# Variable declaration
old_number = 1
current_number = 1

print ('1')

# Calculation and result
while (current_number < 100) :
print (current_number)
next_number = current_number + old_number

old_number = current_number
current_number = next_number

1
1
2
3
5
8
13
21
34
55
89


### Example 6.2, Page number: 115¶

In :
# Variable declaration
total = 0
i = 0

# Calculation
while (i < 10) :
item = 1

if item == 0 :
break

total += item
print ('Total: %d' % total)
i = i + 1

# Result
print ('Final total: %d' % total)

Total: 1
Total: 2
Total: 3
Total: 4
Total: 5
Total: 6
Total: 7
Total: 8
Total: 9
Total: 10
Final total: 10


### Example 6.3, Page number: 116¶

In :
# Variable declaration
total = 0
minus_items = 0
i = 0

# Calculation
while (i < 10) :
item = 1

if item == 0 :
break

if item < 0 :
minus_items += 1
continue

total += item
print ('Total: %d' % total)
i = i + 1

# Result
print ('Final total: %d' % total)
print ('with %d negative items omitted' % minus_items)

Total: 1
Total: 2
Total: 3
Total: 4
Total: 5
Total: 6
Total: 7
Total: 8
Total: 9
Total: 10
Final total: 10
with 0 negative items omitted


### Example 6.4, Page number: 118¶

In :
# Variable declaration
balance_owed = 100

# Calculation and result
if balance_owed == 0 :
print ('You owe nothing.')
else :
print ('You owe %d dollars.' % balance_owed)

You owe 100 dollars.