PHP mathematics commonly used functions

Definition and usage: The abs() function returns the absolute value of a number.

Syntax: abs(x), the code is as follows:

$abs=abs(-3.2); //$abs=3.2

$abs2= abs(5); //$abs2=5

$abs3=abs(-5); ceil(x)

Parameter description

x is required, a number.

Instructions: Return the next integer that is not less than x. If x has a decimal part, it will be rounded up. The type returned by ceil() is still float, because The range of float values ​​is usually larger than that of integer. The example code is as follows:

echo ceil(5);
";

echo ceil(6.999);                                                                                                                                                                                            The floor() function rounds down to the nearest integer.

Syntax: floor(x)

Parameter description

x required, A number.

Explanation: Return the next integer not greater than x, round off the decimal part of x, the type returned by floor() is still float, because the range of float values ​​is usually larger than integer.

echo floor(4); //4

echo "
";

echo floor(3.3);

Definition and usage

fmod() function returns the floating point remainder of division.

Syntax: fmod(x,y)

Parameter description

x required, a number.

y required, a number.

Description: Returns the floating-point remainder obtained by dividing the dividend (x) by the divisor (y). The definition of the remainder (r) is: x = i * y + r, where i is an integer. If y is a non-zero value, then r and x have the same sign and their quantitative value is less than y, the code is as follows:

$x=4.7;                                                                                                                   using using with use with using             to having ’s ’ using ’s having the same sign ’s to ‐   ‐ ‐ ‐ //Define value 2

$r=fmod($x,$y) ; 

Syntax: log10(x)

Parameter description

x is required, a number.

Description: Returns the base 10 logarithm of parameter x, the code is as follows:

$num1=100;

$num2= 1000;

$num3=3;

$result1=log10($num1);

$result2=log10($num2);

$result3=log10($num3);

echo "$num1 to 10 The base 10 logarithm of $num2 is $result2";

echo "
";

echo "$num2 The base 10 logarithm of $num2 is $result2"; echo "The base 10 logarithm of $num3 is $result3";

echo "
";

log() returns the natural logarithm.

Syntax: log(x,base)

Parameter description

x required, a number.

base optional, if this parameter is specified, logbasex is returned.

Note: If the optional parameter base is specified, log() returns logbasex, otherwise log() returns parameter x The natural logarithm of The natural logarithm of the value

echo "
";

echo log(1); //Returns the natural logarithm of the specified value

echo "
"; (0);                     //Returns the natural logarithm of the specified value

echo "
";

echo log(-1); sqrt (9);

var_dump( pow(2, 8)); //Output 256

echo "
";

echo pow(-1,20); //Output 1

echo "
";

echo pow(0,0); //Output 1

echo "
";

echo pow(-1, 4.5); //Return error