Calculates Euler’s number raised to the supplied exponent.
What Is exp() in PHP?
Calculates Euler’s number raised to the supplied exponent.
Its syntax is:
exp(float $num): floatParameters:
$num— Accepted as float; required argument.
Return type: float. Large positive exponents overflow to INF; the result is a floating-point approximation.
Availability: Core PHP.
Example 1: Basic Usage
<?php
echo round(exp(1), 4);
Output:
2.7183Large positive exponents overflow to INF; the result is a floating-point approximation.
Example 2: A Different Input
<?php
echo round(exp(0), 2);
Output:
1Large positive exponents overflow to INF; the result is a floating-point approximation.
Practical Example: Applying It in a Program
<?php
$rates = [0.02, 0.05, 0.1]; foreach ($rates as $rate) { echo round(100 * exp($rate), 2) . PHP_EOL; }
Output:
102.02
105.13
110.52Large positive exponents overflow to INF; the result is a floating-point approximation.
Important Behavior and Edge Cases
- Key behavior: Large positive exponents overflow to INF; the result is a floating-point approximation.
- Environment: Core PHP.
Comparison With Related Functions
| Function | Purpose |
|---|---|
exp() | Calculates Euler’s number raised to the supplied exponent. |
expm1() | expm1(x) computes exp(x)-1 with better precision near zero; exp(x) returns e raised to x. |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
| Ignoring this behavior: Large positive exponents overflow to INF; the result is a floating-point approximation | Large positive exponents overflow to INF; the result is a floating-point approximation. |
Key Takeaways
- Calculates Euler’s number raised to the supplied exponent.
- Large positive exponents overflow to INF; the result is a floating-point approximation.
- Core PHP.
Summary: Large positive exponents overflow to INF; the result is a floating-point approximation.