Computer disk defragmentation, learning and defragmentation of several internal functions of PHP mathematical calculations

round
round - Round floating point numbers. The round function syntax is as follows:
round(float,precision)
The parameter precision represents the number of precision digits to be maintained after the decimal point. If the parameter precision is not written, it means rounding to an integer, for example:
echo round(3.4); // 3echo round(3.5); // 4echo round(3.6); // 4
If precision is 2, it means rounding to a decimal point Last 2 digits. An example is as follows:
echo round(1.95583, 2); // 1.96
If the parameter precision is a negative number, it means rounding to the decimal point. For example:
echo round(1241757, -3); // 1242000
floor
floor - Rounding by rounding. The syntax of the floor function is as follows:
floor (value)
The floor function returns the largest integer that is not greater than value, that is, the decimal part of value is rounded off. Examples are as follows:
echo floor(4); //4
echo floor(4.3); // 4echo floor(9.999); // 9
ceil
ceil - round to the nearest integer. The syntax of the ceil function is as follows:
ceil (value)
ceil function returns the smallest integer that is not less than value. Examples are as follows:
echo ceil(4); //4
echo ceil(4.3); // 5echo ceil(9.999); // 10
pow
pow - Exponentiation. The syntax of the pow function is as follows:
pow (base,exp)
pow function returns base raised to the power of exp. The following example represents finding 2 raised to the 8th power, and the returned result is 256.
echo pow(2, 8); // 256
rand
rand - Generate a random integer. The syntax of rand function is as follows:
rand (min,max)
rand function returns a random integer between the minimum value min and the maximum value max (including min, max). For example, the following example returns a random integer between 2 and 6.
echo rand(2,6);
max
max - Returns the largest value in the parameter.
If the max function has only one parameter and it is an array, max returns the largest value in the array. An example of the
max function is as follows:
echo max(1, 3, 5, 6, 7); // 7echo max(array(2, 4, 5)); // 5
min
min - Returns the minimum value in the parameters .
If the min function has only one parameter and it is an array, min returns the smallest value in the array. An example of the
min function is as follows:
echo min(1, 3, 5, 6, 7); // 1echo min(array(2, 4, 5)); // 2
decbin
decbin - Convert decimal to binary. The syntax of the decbin function is as follows:
decbin (number)
decbin returns a string, that is, the binary representation of the parameter number. An example is as follows:
echo decbin(12);
DE>decbin(12)DE> The returned result is:
1100
bindec
bindec - Binary to decimal conversion. The syntax of the bindec function is as follows:
bindec (binary_string) The
bindec function converts the binary string binary_string into a decimal integer. Examples are as follows:
echo bindec('110011'); //51
dechex, hexdec
dechex - Convert decimal to hexadecimal.
hexdec - Convert hexadecimal to decimal.
dechex, hexdec function examples are as follows:
echo dechex(47); //2f
echo hexdec('2f'); //47
decoct, octdec
decoct - Convert decimal to octal
octdec - Convert octal to decimal
decoct , an example of the octdec function is as follows:
echo decoct(12); //14
echo octdec('14'); //12

The above introduces the defragmentation of computer disks and the learning and defragmentation of several internal functions of PHP mathematical calculations, including the content of defragmentation of computer disks. I hope it will be helpful to friends who are interested in PHP tutorials.