PHP PHPUnit assertNan()用法及代码示例

assertNan()函数是PHPUnit中的内置函数，用于断言变量是否为NAN。如果变量为NAN，则此断言将返回true，否则返回false。如果为真，则通过断言的测试用例，否则测试用例失败。

用法:

assertNan(mixed $variable[, string $message = ''])

参数：此函数接受上述和以下描述的两个参数：

• $Variable:此参数代表任何类型的变量。
• $message:此参数采用字符串值。当测试用例失败时，此字符串消息将显示为错误消息。

以下示例说明了PHPUnit中的assertNan()函数：

范例1：

<?php  
use PHPUnit\Framework\TestCase;  
    
class GeeksPhpunitTestCase extends TestCase  
{  
    public function testNegativeTestcaseForassertNan()  
    {  
        $variable = 0*0;  
    
        // Assert function to test whether given  
        // variable is (NAN) or not 
        $this->assertNan( 
          $variable, 
          "variable is (NAN) or not"
        );  
    }  
}  
    
?> 

输出：

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::testNegativeTestcaseForassertNan
variable is (NAN) or not
Failed asserting that 0 is nan.

/home/lovely/Documents/php/test.php:15

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

范例2：

<?php  
use PHPUnit\Framework\TestCase;  
    
class GeeksPhpunitTestCase extends TestCase  
{  
    public function testPositiveTestcaseForassertNan()  
    {  
        $variable = NAN;  
    
        // Assert function to test whether given  
        // variable is (NAN) or not 
        $this->assertNan( 
          $variable, 
          "variable is (NAN) or not"
        );  
    }  
}  
    
?> 

输出：

PHPUnit 8.5.8 by Sebastian Bergmann and contributors.

.                                                  1 / 1 (100%)

Time:87 ms, Memory:10.00 MB

OK (1 test, 1 assertion)

参考：https://phpunit.readthedocs.io/en/9.2/assertions.html#assertnan