Echo (Echo input)

The echo command is used for displaying a line of text/string that is included in the argument.

echo with string

When an argument is a string, the echo command returns the string itself.

echo ABC

ABC

echo with variable

When an argument is a variable, use $ before the variable. the echo command returns an assigned string to the variable.

ABC=56
echo $ABC

56

echo with string and variable

You can connect strings and variables in the echo command.

ABC=56
echo ABC$ABC

ABC56

" " double quotation and ' ' single quotation

You can connect strings or variables with special characters or spaces with the " " or ' ' quotation; however, there is a slight difference.

" " double quotation

with the " " quotation, variables are converted to assigned strings.

ABC=56
echo "ABC$ABC ABC"

ABC56 ABC

‘ ’ single quotation

with the ' ' quotation, variables are not converted to assigned strings. $ is considered as a part of the strings.

ABC=56
echo 'ABC$ABC ABC'

ABC$ABC ABC