Function Parameters
Part of the Fundamentals section of Coddy's PHP journey — lesson 62 of 71.
The sayHello function from the previous lesson always does the same thing. But what if you want to greet different people? Parameters let you pass data into a function, making it flexible and dynamic.
Parameters are variables listed inside the parentheses when you declare a function. When you call the function, you provide values (called arguments) that get assigned to those parameters:
<?php
function greet($name) {
echo "Hello, $name!\n";
}
greet("Alice");
greet("Bob");
?>This outputs:
Hello, Alice!
Hello, Bob!The parameter $name acts like a placeholder. Each time you call greet(), the argument you pass replaces that placeholder inside the function.
Functions can accept multiple parameters, separated by commas:
<?php
function introduce($name, $age) {
echo "$name is $age years old.\n";
}
introduce("Alice", 25);
introduce("Bob", 30);
?>This outputs:
Alice is 25 years old.
Bob is 30 years old.When calling a function with multiple parameters, the order matters—the first argument goes to the first parameter, the second to the second, and so on.
Challenge
EasyRead three lines of input:
- A person's name (e.g.,
Alice) - A city name (e.g.,
Paris) - A year (e.g.,
2020)
Create a function called describePerson that accepts three parameters: $name, $city, and $year. The function should print a message in the following format:
[name] moved to [city] in [year].Call the function with the input values.
Example 1:
If the inputs are Alice, Paris, and 2020, the output should be:
Alice moved to Paris in 2020.Example 2:
If the inputs are Bob, Tokyo, and 2018, the output should be:
Bob moved to Tokyo in 2018.Example 3:
If the inputs are Emma, New York, and 2015, the output should be:
Emma moved to New York in 2015.Cheat sheet
Parameters are variables listed inside the parentheses when declaring a function. When calling the function, you provide values (arguments) that get assigned to those parameters:
<?php
function greet($name) {
echo "Hello, $name!\n";
}
greet("Alice");
?>Functions can accept multiple parameters, separated by commas:
<?php
function introduce($name, $age) {
echo "$name is $age years old.\n";
}
introduce("Alice", 25);
?>When calling a function with multiple parameters, the order matters—the first argument goes to the first parameter, the second to the second, and so on.
Try it yourself
<?php
// Read input
$name = trim(fgets(STDIN));
$city = trim(fgets(STDIN));
$year = trim(fgets(STDIN));
// TODO: Create a function called describePerson that accepts three parameters
// ($name, $city, $year) and prints the message in the required format
// Call the function with the input values
?>
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Fundamentals
4Comparison & Logical Operators
Comparison OperatorsEquality & IdentityLogical Operators Part 1Logical Operators Part 2Recap - Simple Logic2Variables and Data Types
NumbersStrings and QuotesBooleansNaming ConventionsRecap - Variable InitEmpty VariablesString ConcatenationGetting User InputCast to Different Types5Conditional Logic
If StatementIf - ElseThe Ternary OperatorNull Coalescing OperatorSwitch StatementRecap - Making Decisions3Basic Operators
Arithmetic OperatorsModulo OperatorExponentiation OperatorCombined AssignmentIncrement/DecrementOperator PrecedenceRecap - Simple CalculationsString Operators