Variable assignment (no spaces around =) in Bash Scripting - Step-by-Step Execution

Concept Flow - Variable assignment (no spaces around =)

Start

↓

Write variable name

↓

Write = with NO spaces

↓

Write value

↓

Variable assigned

↓

Use variable later

Assign a value to a variable by writing name=value with no spaces around =, then use the variable.

Execution Sample

Bash Scripting

name=John
age=30

# Print variables
echo $name

Assigns values to variables 'name' and 'age' without spaces, then prints the value of 'name'.

Execution Table

Step	Code Line	Action	Variable	Value	Output
1	name=John	Assign value to variable 'name'	name	John
2	age=30	Assign value to variable 'age'	age	30
3	echo $name	Print value of 'name'	name	John	John
4		End of script

💡 Script ends after printing the value of 'name'.

Variable Tracker

Variable	Start	After Step 1	After Step 2	Final
name	undefined	John	John	John
age	undefined	undefined	30	30

Key Moments - 2 Insights

Why can't I put spaces around the = sign in bash variable assignment?

In bash, spaces around = cause errors because the shell treats spaces as separators. See execution_table steps 1 and 2 where assignment works only without spaces.

What happens if I try to assign with spaces like 'name = John'?

Bash treats 'name' as a command and '= John' as arguments, causing an error. This is why no spaces are allowed, as shown in the successful assignments in execution_table.

Visual Quiz - 3 Questions

Look at the execution table, what is the value of 'age' after step 1?

A 30

B undefined

C John

D empty string

💡 Hint

Check the variable_tracker table under 'age' after step 1.

At which step does the script print output?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Output' column in the execution_table.

If you add spaces like 'name = John', what will happen?

A Bash throws an error or treats 'name' as a command

B Variable 'name' gets assigned 'John'

C Variable 'name' gets assigned '= John'

D Variable 'name' gets assigned empty string

💡 Hint

Refer to key_moments explanation about spaces around '='.

Concept Snapshot

Bash variable assignment:
Use name=value with NO spaces around '='.
Spaces cause errors because shell splits tokens.
Access variable with $name.
Example:
name=John
age=30
echo $name

Full Transcript

In bash scripting, to assign a value to a variable, write the variable name, then an equal sign with no spaces, then the value. For example, name=John assigns 'John' to the variable 'name'. Spaces around the equal sign cause errors because bash treats spaces as separators. After assignment, you can use the variable by prefixing it with a dollar sign, like echo $name to print its value. The execution table shows step-by-step how variables 'name' and 'age' get assigned and how the value of 'name' is printed. Remember, no spaces around '=' in assignments.