Bash - check if number is not equal

In this article, we would like to show you how to check if number is not equal to another number in Bash.

Practical example

In this example, we use -ne operator to check if number is not equal to another number inside if statement.

script.sh file:

#!/bin/bash

number=3

if [ "$number" -ne 5 ]; then
    echo "$number is not equal to 5"
fi

Note: this approach should be used in POSIX shells where other solutions may not work.

Run in command line:

./script.sh

Output:

3 is not equal to 5

Altermative notation

1. test based solution

#!/bin/bash

number=3

if test "$number" -ne 5; then
    echo "$number is not equal to 5"
fi

Note: [ ] notation is shorthand of test command.

2. [[ ]] based solution

#!/bin/bash

number=3

if [[ "$number" -ne 5 ]]; then
    echo "$number is not equal to 5"
fi

Note: [[ ]] notation is like extended test command, adding additional features (e.g. regular expressions).

3. (( )) based solution

#!/bin/bash

number=3

if (( "$number" != 5 )); then
    echo "$number is not equal to 5"
fi

Note: (( )) notation was created to simplyfy conditions (like in C language).

See also

1. Bash - compare number variable to another number