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Function Parameters: Pass Data To Functions

Functions can take parameters. Pass data to them. Use it.

Here's the thing: Function parameters work like script arguments. $1, $2, etc. Simple.

Basic Parameters​

function greet() {
    echo "Hello, $1"
}

greet "John"

My take: $1 is first parameter. $2 is second. Like script arguments.

Multiple Parameters​

function add() {
    sum=$(( $1 + $2 ))
    echo "$sum"
}

add 5 10

My take: Multiple parameters work. Use them.

All Parameters​

function process_all() {
    for arg in "$@"; do
        echo "$arg"
    done
}

process_all "one" "two" "three"

My take: $@ is all parameters. Use it.

Common Patterns​

Required Parameters​

function process() {
    if [ $# -lt 2 ]; then
        echo "Usage: process <arg1> <arg2>"
        return 1
    fi
    # Use $1 and $2
}

What's Next?​

Now that you understand parameters, let's talk about Return Values.

Personal note: Function parameters seemed complex at first. Then I learned: they're like script arguments. Now I use them constantly. They're simple. Learn them.