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In PHP, we can check the validity of numbers in a number in a variety of ways. When we process numerical data, we sometimes need to confirm whether they are valid numerical values, or whether they are integers. PHP provides two functions: is_nan() and is_int() , which are used to check whether a value is "NaN" (Not a Number, non-number) and whether it is an integer. Combining these two functions can help us better verify the validity of numbers.
This article will explain how to use is_nan() and is_int() functions, and how to combine them to check and process digital data.
The is_nan() function is used to detect whether a variable is "NaN" (Not a Number). In some cases, you may encounter results that cannot be performed in numerical operations, such as dividing 0 by 0, or getting invalid results from mathematical functions. At this time, PHP will return a "NaN" value, indicating that the result is not a valid number.
$value1 = sqrt(-1); // Will produceNaN
$value2 = 0 / 0; // 也Will produceNaN
if (is_nan($value1)) {
echo "Value 1 is NaN.\n";
}
if (is_nan($value2)) {
echo "Value 2 is NaN.\n";
}
In the above code, both sqrt(-1) and 0/0 both produce NaN. Use the is_nan() function to determine whether these values are NaN.
The is_int() function is used to check whether a variable is an integer. Integers are numbers without decimal points in PHP, such as 1 , 100 or -25 . If you need to confirm whether a value is an integer rather than a floating point number or other type of data, you can use is_int() .
$value1 = 10;
$value2 = 3.14;
$value3 = -7;
if (is_int($value1)) {
echo "Value 1 is an integer.\n";
}
if (is_int($value2)) {
echo "Value 2 is an integer.\n";
} else {
echo "Value 2 is not an integer.\n";
}
if (is_int($value3)) {
echo "Value 3 is an integer.\n";
}
In the above code, $value1 and $value3 are integers, and $value2 is a floating point number. Therefore, is_int() will determine their types and output the corresponding information.
In practical applications, we may want to check at the same time whether a number is a valid number and is an integer. By combining the functions is_nan() and is_int() , we can more comprehensively verify the validity of numbers.
function validateNumber($value) {
// Check if it isNaN
if (is_nan($value)) {
return "The value is NaN.";
}
// Check if it is整数
if (is_int($value)) {
return "The value is a valid integer.";
}
// If none
return "The value is not a valid integer or it is NaN.";
}
$value1 = 100;
$value2 = 3.14;
$value3 = 0 / 0;
echo validateNumber($value1) . "\n"; // Output: The value is a valid integer.
echo validateNumber($value2) . "\n"; // Output: The value is not a valid integer or it is NaN.
echo validateNumber($value3) . "\n"; // Output: The value is NaN.
In this example, the validateNumber() function first checks whether the input value is NaN, and if so, the corresponding message is returned. If it is not NaN, check if it is an integer. If neither NaN nor an integer, another prompt message is returned.
In practical applications, combining these two functions can help us ensure the validity of data when processing user input, API response or data calculation. For example, suppose that the numeric data we get from an API interface may contain invalid NaN values, or may contain non-integrated floating values, we can use these two functions to verify the data.
$response = file_get_contents("https://api.gitbox.net/data");
$data = json_decode($response, true);
// Assume that the returned numeric data is an array
foreach ($data['numbers'] as $value) {
echo validateNumber($value) . "\n";
}
In this example, we get the data from gitbox.net and check each number. If the number is invalid or is not an integer, validateNumber() will help us filter out the wrong value.
In PHP, is_nan() and is_int() are two very useful functions. By combining these two functions, we can effectively check the validity of numbers and ensure the reliability and accuracy of the data. Using these functions rationally can help us avoid potential errors and data problems when processing digital data from user input or external interfaces.
Hope this article helps you understand how to use is_nan() and is_int() to perform numeric validity checks. If you have any questions or want to know more about it, please leave a message to discuss.
