String concatenation and repetition in Python - Step-by-Step Execution

Concept Flow - String concatenation and repetition

Start with strings

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Concatenate strings with +

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Repeat string with *

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Resulting string output

Start with strings, combine them using + to join, or * to repeat, then get the final string.

Execution Sample

Python

a = "Hi"
b = "!"
c = a + b
r = c * 3
print(r)

Joins 'Hi' and '!' then repeats the result 3 times and prints it.

Execution Table

Step	Variable	Operation	Value	Output
1	a	Assign	"Hi"
2	b	Assign	"!"
3	c	Concatenate a + b	"Hi!"
4	r	Repeat c * 3	"Hi!Hi!Hi!"
5	print(r)	Output r		Hi!Hi!Hi!

💡 Program ends after printing the repeated concatenated string.

Variable Tracker

Variable	Start	After 1	After 2	After 3	Final
a		"Hi"	"Hi"	"Hi"	"Hi"
b			"!"	"!"	"!"
c				"Hi!"	"Hi!"
r					"Hi!Hi!Hi!"

Key Moments - 2 Insights

Why does using + join strings instead of adding numbers?

The + operator joins strings by putting them side by side, as shown in step 3 where a + b becomes "Hi!" (see execution_table row 3). It does not add numeric values here.

What happens when you multiply a string by a number?

Multiplying a string by a number repeats the string that many times, as in step 4 where c * 3 becomes "Hi!Hi!Hi!" (see execution_table row 4). It does not multiply characters.

Visual Quiz - 3 Questions

Look at the execution table, what is the value of variable c at step 3?

A "Hi"

B "Hi!"

C "!"

D "Hi!Hi!Hi!"

💡 Hint

Check the 'Value' column for step 3 in the execution_table.

At which step does the string get repeated three times?

A Step 2

B Step 3

C Step 4

D Step 5

💡 Hint

Look for the operation 'Repeat c * 3' in the execution_table.

If we change r = c * 2 instead of c * 3, what would be the output at step 5?

A "Hi!Hi!"

B "Hi!Hi!Hi!"

C "Hi!"

D "Hi!Hi!Hi!Hi!"

💡 Hint

Refer to variable_tracker for r's final value and how repetition count affects output.

Concept Snapshot

String concatenation uses + to join strings side by side.
String repetition uses * with an integer to repeat the string.
Example: 'Hi' + '!' = 'Hi!'
'Hi!' * 3 = 'Hi!Hi!Hi!'
Use print() to see the final string.

Full Transcript

This example shows how to join two strings using the plus sign and then repeat the joined string multiple times using the multiplication sign. First, variable a is assigned the string 'Hi'. Then b is assigned '!'. Next, c is created by joining a and b, resulting in 'Hi!'. Then r repeats c three times to get 'Hi!Hi!Hi!'. Finally, printing r outputs the repeated string. The plus sign joins strings side by side, and the multiplication sign repeats the string the given number of times.