Arrays

intro

An array is a list of items.
Make a file friends.sh

#!/bin/bash

# the array
hobbies=(coding reading learning writing "hanging with dena")

# get itme by 0-based-index
echo My third hobby is ${hobbies[2]}

# loop with for-in
for h in ${hobbies[@]}
  do
	  echo hobby: $h
  done
  
echo "I have ${#hobbies[*]} hobbies"

Run the file with . friends.sh

A While Loop

Here, a while loop inside a runnable bash script.

make a file guess-it.sh, where the script will live:

# like "let" syntax in js -> let "NUM_TO_GUESS = ${RANDOM} % 10 + 1"
# NUM_TO_GUESS=$(( $RANDOM % 10 + 1 ))
# note the $(()), thats a shorthand syntax
NUM_TO_GUESS=$(( $RANDOM % 10 + 1 ))
GUESSED_NUM=0

echo "guess a number between 1 and 10"

while [ $NUM_TO_GUESS -ne $GUESSED_NUM ]
do
  read -p "your guess: " GUESSED_NUM
done

echo "you got it!"

run the bash script file like this...

$ . guess-it.sh 
guess a number between 1 and 10
your guess: 3
your guess: 8
your guess: 2
you got it!

Tags:

linux