Question

Write a detail note on for loop?

Answer 1

for loop:

• for loop is the most comfortable loop. It is also an entry check loop.
• The condition is checked in the beginning and the body of the loop
  (statements-block 1) is executed if it is only True otherwise the loop is not executed.

Syntax:

for counter_variable in
sequence:
statements – block 1
[else: # optional block statements – block 2]

• The counter, variable mentioned in the syntax is similar to the control variable that we used in the for loop of C++ and the sequence refers to the initial, final, and increment value.
• Usually in Python, for loop uses the range () function in the sequence to specify the initial, final, and increment values, range () generates a list of values starting from start till stop-1.

The syntax of range() follows:

range (start, stop, [step])
Where,
start – refers to the initial value
stop – refers to the final value
step – refers to increment value,
this is an optional part.

Examples for range():

range (1,30,1) – will start the range of values from 1 and end at 29 range (2,30,2) – will start the range of values from 2 and end at 28 range (30,3,-3) – will start the range of values from 30 and end at 6E range (20) – will consider this value 20 as the end value ( or upper limit) and starts the range count from 0 to 19 (remember always range () will work till stop -1 value only)

Example-Program:

#Program to illustrate the use of for loop – to print single digit even number
for i in range (2,10,2):
print (i, end=”)

Output:
2468

Flowchart-for loop execution:

For loop execution