Common php mathematical functions

Definitions and usage of common php functions: abs () 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); // $ abs3 = 5

Definition and usage: The ceil () function rounds up to the nearest integer.

Syntax ceil (x)

Parameter description

X is required. it is a number.

Note: the return value is the next integer not less than x. If x has a decimal part, the return value of ceil () is still float, because the float value range is usually larger than integer, the instance code is as follows:

Echo ceil (5); // 5

Echo"
";

Echo ceil (3.3); // 4

Echo"
";

Echo ceil (6.999); // 7

The floor () function is rounded down to the nearest integer.

Syntax: floor (x)

Parameter description

X is required. it is a number.

Note: If the return value is not greater than the next integer of x, the fractional part of x is rounded up, and the type returned by floor () is still float, because the float value range is usually larger than integer.

Echo floor (4); // 4

Echo"
";

Echo floor (3.3); // 3

Echo"
";

Echo floor (6.999); // 6

Definition and usage

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

Syntax: fmod (x, y)

Parameter description

X is required. it is a number.

Y is required. it is a number.

Description: return the remainder of the floating point number obtained by dividing the devisor (x) by the devisor (y). The remainder (r) is defined as x = I * y + r, where I is an integer, if y is a non-zero value, the symbols of r and x are the same and the number of values is less than y. the code is as follows:

$ X = 4.7; // defines the value 1.

$ Y = 1.3; // defines the value 2.

$ R = fmod ($ x, $ y); // perform the remainder operation.

The remainder of echo $ x. "divided by". $ y. "is:". $ r; // output result

The base-10 logarithm of log10.

Syntax: log10 (x)

Parameter description

X is required. it is 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 base-10 logarithm $ result1 ";

Echo"
";

Echo "$ num2 base-10 logarithm $ result2 ";

Echo"
";

Echo "$ num3 base-10 logarithm $ result3 ";

Echo"
";

Log () returns the natural logarithm.

Syntax: log (x, base)

Parameter description

X is required. it is 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 the natural logarithm of parameter x. The instance code is as follows:

Echo log (2.7183); // returns the natural logarithm of the specified value.

Echo"
";

Echo log (2); // returns the natural logarithm of the specified value.

Echo"
";

Echo log (1); // returns the natural logarithm of a specified value.

Echo"
";

Echo log (0); // returns the natural logarithm of the specified value.

Echo"
";

Echo log (-1); // returns the natural logarithm of the specified value.

//

Echo sqrt (9); // output 3

Echo"
";

Echo sqrt (10); // 16227766...

// Open source code phpfensi.com

//

Var_dump (pow (2, 8); // 256 output

Echo"
";

Echo pow (-1, 20); // output 1

Echo"
";

Echo pow (0, 0); // output 1

Echo"
";

Echo pow (-1, 4.5); // An error is returned.