how to check if a number is bigger thananother number in bash code example

Example 1: 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

Example 2: bash if larger than

# In bash, you should do your check in arithmetic context:

if (( a > b )); then
    ...
fi

# For POSIX shells that don't support (()), you can use -lt and -gt.

if [ "$a" -gt "$b" ]; then
    ...
fi