Break Statement

The break statement alters the normal flow of execution: it terminates the current loop immediately and resumes execution at the statement following that loop. The rest of the loop body for the current iteration is abandoned, and no further iterations occur — regardless of what the loop's condition says. The flowchart for break (printed as Figure 6.5 in the book) shows the moment break is encountered, control jumps straight out of the loop body to the statement after the loop.

break in a for loop

# Demonstrate break inside a for loop
n = 0
for n in range(10):
    n = n + 1
    if n == 8:
        break
    print('Num has value ' + str(n))
print('Encountered break!! Out of loop')

Num has value 1
Num has value 2
Num has value 3
Num has value 4
Num has value 5
Num has value 6
Num has value 7
Encountered break!! Out of loop

Although range(10) could drive ten iterations, the loop stops the moment the value reaches 8: the break executes, the print inside the loop is skipped for that pass, and control lands on the final print after the loop.

break as a deliberate exit from while True

break is the natural way out of a loop whose condition never turns false on its own. Here a while True loop keeps accepting numbers and accumulating their sum; the first negative entry ends the input:

# Sum positive numbers; a negative number ends the loop
value = 0
total = 0
print("Enter numbers to find their sum, negative number ends the loop:")
while True:
    value = int(input())      # int() typecasts the input string to integer
    if value < 0:
        break
    total += value
print("Sum =", total)

Enter numbers to find their sum, negative number ends the loop:
3
4
5
-1
Sum = 12

The negative number itself is not added — break fires before the accumulation line.

break to stop searching early — prime check

When testing whether a number is prime, the first divisor found already settles the answer, so there is no need to check any further. A flag variable records what was discovered:

# Check whether a given number is prime
num = int(input("Enter the number to be checked: "))
found = 0                     # presume num is a prime number
if num > 1:
    for d in range(2, int(num / 2)):
        if num % d == 0:
            found = 1         # num is not a prime number
            break             # no need to check any further
    if found == 1:
        print(num, "is not a prime number")
    else:
        print(num, "is a prime number")
else:
    print("Entered number is <= 1, execute again!")

Sample runs:

Enter the number to be checked: 20
20 is not a prime number

Enter the number to be checked: 19
19 is a prime number

Enter the number to be checked: 2 …