If Condition branch in bash

There are three different forms:

The first of the simplest forms is:

    if [expression]; Then

        statements

    fi

The second form is:

    if [expression1]; Then

         statements1

    else

         statements0

    fi

The third form is:

    if [expression1]; Then

         statements1

    elif [expression2], then

         statements2

    elif [Expression3]; then

         statements3

    else

         statements0

    fi

The sample code for these three forms is as follows:

bash-4.2@conditionals$ cat Main1.bash
#!/bin/bash
num=2
if [$num = ' 1 ']; then
   echo "expression Evaluated True. "
Fi
bash-4.2@conditionals$ cat main2.bash
#!/bin/bash
value=2
If [value = ' 1 ']; then
    echo ' value is 1 '
else
    echo ' value is 2 '
fi

bash-4.2@conditionals$ cat main3.bash
#!/bin/bash
value= 3
If [value = ' 1 ']; then
    echo ' value was 1 '
elif [value = ' 2 ']; then
    echo ' value is 2 '
Else
  echo ' value is 3 '
fi

The output results are as follows:

bash-4.2@conditionals$./main1.bash;. /main2.bash;. /main3.bash 
value is 2
value is 3