PHPUnit assertLessThan() Function

The assertLessThan() function is a builtin function in PHPUnit and is used to assert whether the actually obtained value is less than the expected value or not. This assertion will return true in the case if the actual value is less than the expected value else returns false. In case of true the asserted test case got passed else test case got failed.

Syntax:

assertLessThan(mixed $expected, mixed $actual
[, string $message = ''])

Parameters: This function accepts three parameters as mentioned above and described below:

• $expected: This parameter is of any type of numeric value which represents the expected data.
• $actual: This parameter is of any type of numeric value which represents the actual data.
• $message: This parameter takes a string value. When the test case got failed this string message got displayed as an error message.

Below examples illustrate the assertLessThan() function in PHPUnit:

Example 1:

<?php 
use PHPUnit\Framework\TestCase; 
  
class GeeksPhpunitTestCase extends TestCase 
{ 
    public function testNegativeTestcaseForassertLessThan()
    {    $expected = 11; 
        $actual = 22;
  
        // Assert function to test whether expected 
        // value is less than actual or not 
        $this->assertLessThan( 
            $expected, 
            $actual, 
            "actual value is not less than expected"
        ); 
    } 
} 
  
?> 

Output:

PHPUnit 8.5.8 by Sebastian Bergmann and contributors.

F                                                  1 / 1 (100%)

Time: 88 ms, Memory: 10.00 MB

There was 1 failure:

1) GeeksPhpunitTestCase::testNegativeTestcaseForassertLessThan
actual value is not less than expected
Failed asserting that 22 is less than 11.

/home/lovely/Documents/php/test.php:16

FAILURES!
Tests: 1, Assertions: 1, Failures: 1.

Example 2:

<?php 
use PHPUnit\Framework\TestCase; 
  
class GeeksPhpunitTestCase extends TestCase 
{ 
    public function testPositiveTestcaseForassertLessThan()
    {    $expected = 22; 
        $actual = 11;
  
        // Assert function to test whether expected 
        // value is less than actual or not 
        $this->assertLessThan( 
            $expected, 
            $actual, 
            "actual value is not less than expected"
        ); 
    } 
} 
  
?> 

Output:

PHPUnit 8.5.8 by Sebastian Bergmann and contributors.

.                                                  1 / 1 (100%)

Time: 88 ms, Memory: 10.00 MB

OK (1 test, 1 assertion)