Bash: How to compare arguments with if statement?

Question

I'm trying to compare an argument in bash under OSX using the following code...

 #!/bin/bash

if ["$1" == "1"]
then
        echo $1
else
        echo "no"
fi

But I keep getting the following error

$bash script.sh 1

script.sh: line 3: [1: command not found
no

How do I stop it from trying to evaluate "1"?

Answer 1

[ is a test command, so you need a space between [ and "$1", as well as a space between "1" and the closing ]

Edit

Just to clarify, the space is needed because [ is a different syntax of the test bash command, so the following is another way of writing the script:

#!/bin/bash

if test "$1" == "1"
then
        echo $1
else
        echo "no"
fi

Which can be further simplified to

#!/bin/bash
[ "$1" == "1" ] && echo "$1" || echo "no"