How to Use sprintf in PHP: Syntax and Examples

In PHP, sprintf formats a string by replacing placeholders with variable values and returns the formatted string. You use it by providing a format string with placeholders like %s for strings or %d for integers, followed by the values to insert.

Syntax

The sprintf function takes a format string and a list of values. The format string contains placeholders that start with % and specify the type of value to insert.

• %s: Insert a string
• %d: Insert an integer
• %f: Insert a floating-point number
• %.2f: Floating-point with 2 decimal places

The function returns the formatted string without printing it.

php

string sprintf ( string $format , mixed ...$values )

Example

This example shows how to format a string with a name and age using sprintf. It inserts the string and integer into the placeholders.

php

<?php
$name = "Alice";
$age = 30;
$formatted = sprintf("My name is %s and I am %d years old.", $name, $age);
echo $formatted;
?>

Output

My name is Alice and I am 30 years old.

Common Pitfalls

Common mistakes include:

• Using the wrong placeholder type (e.g., %d for a string).
• Not providing enough values for the placeholders.
• Expecting sprintf to print output instead of returning it.

Always check that your placeholders match the types of the values you pass.

php

<?php
// Wrong: using %d for a string
$name = "Bob";
$wrong = sprintf("Name: %d", $name); // This will output 0

// Correct:
$correct = sprintf("Name: %s", $name);
echo $correct;
?>

Output

Name: Bob

Quick Reference

Placeholder	Description	Example
%s	String	"Hello %s"
%d	Integer number	"Age: %d"
%f	Floating-point number	"Price: %.2f"
%%	Literal percent sign	"Progress: 50%%"

Key Takeaways

Use sprintf to format strings by inserting variables into placeholders.

Match placeholder types (%s, %d, %f) with the variable types you provide.

sprintf returns the formatted string; it does not print it directly.

Use %.nf to control decimal places for floating-point numbers.

Always provide enough values for all placeholders in the format string.