if statement

When using if-statements, we are already aware that a check is made where an operator is used to determine how we proceed with the execution.

#if

A very common if-statement. Please enjoy.

#!/usr/bin/env bash
#
# An example script on if statement

# If with values

val1=10

if [[ $val1 -gt 5 ]]
then
    echo "$val1 is greater than 5"
fi

# If with strings

string1="music"
string2="acoustic"

if [[ $string1 = "music" ]]
then
    echo "$string1 spells like music"
fi

if [[ $string1 != "$string2" ]]
then
    echo "$string1 is not the same word as $string2"
fi

#else-if/else

We mix the else-if and else blocks and look at what the design looks like:

#!/usr/bin/env bash
#
# An example script on if/else-if statement

# If/else-if/else with values

val1=5

if [[ $val1 -gt 5 ]]
then
    echo "$val1 is greater than 5"
elif [[ $val1 -lt 5 ]]
then
    echo "$val1 is less than 5"
else
    echo "$val1 is 5"
fi

You can also come across constructions like:

#!/usr/bin/env bash
#
# An example script on if/else-if statement

# If/else-if/else with values
val1=5

if [[ $val1 -gt 5 ]]; then echo "$val1 is greater than 5"
elif [[ $val1 -lt 5 ]]; then echo "$val1 is less than 5"
else echo "$val1 is 5"
fi

It works just as well and validates nicely. The semicolon is used to separate commands on the same row.

#Ternary

Many of you are probably wondering if it can be shortened even more, like a ternary operator. We solve it as follows:

#!/usr/bin/env bash
#
# An example script on ternary variant

val1=10

[[ $val1 -ge 5 ]] && res="greater or equal" || res="less"
echo "$res"

#Revision history