Common mathematical functions in php _ php skills

Source: Internet
Author: User
Tags natural logarithm
This article mainly introduces common php mathematical functions and summarizes examples of definitions and usage of common mathematical functions in the form of examples, which has good learning and reference value, you can refer to the examples in this article to summarize and analyze common php mathematical functions. Share it with you for your reference. The specific analysis is as follows:

Abs () function definition and usage: returns the absolute value of a number.

Syntax: abs (x). The code is as follows:

The code is as follows:

$ Abs = abs (-3.2); // $ abs = 3.2
$ Abs2 = abs (5); // $ abs2 = 5
$ Abs3 = abs (-5); // $ abs3 = 5


Ceil () function definition and usage: rounds up to the nearest integer.

Syntax ceil (x)

Parameters Description
X Required. 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:

The 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)

Parameters Description
X Required. 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.

The code is as follows:

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)

Parameters Description
X Required. a number.
Y Required. 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:

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)

Parameters Description
X Required. a number.

Description: returns the base-10 logarithm of parameter x. The code is as follows:

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)

Parameters 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 the natural logarithm of parameter x. The instance code is as follows:

The 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...
//
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.

I hope this article will help you with PHP programming.

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