compare values on linux command line code example

Example: number compare in bash

#!/bin/bash
# Script to do numeric comparisons
var1=10
var2=20
if [ $var2 -gt $var1 ]
    then
        echo "$var2 is greater than $var1"
fi
# Second comparison
If [ $var1 -gt 30]
    then
        echo "$var is greater than 30"
    else
        echo "$var1 is less than 30"
fi