PHP mobile Internet Development notes (5) basic function libraries

I. mathematical function library ● floor rounding (rounding down) floatfloor (float $ value );? Phpecho (floor (0.60 ). br); echo (floor (0.40 ). br); echo (floor (5 ). br); echo (floor (5.1 ). br); echo (floor (-5.1 ). br); echo (floor (-5.9 ). br )? ● Ceil one-to-one INTEGER (rounded up) floatceil (f

I. mathematical function library ● floor rounding (rounding down) float floor (float $ value );? Phpecho (floor (0.60 ). br); echo (floor (0.40 ). br); echo (floor (5 ). br); echo (floor (5.1 ). br); echo (floor (-5.1 ). br); echo (floor (-5.9 ). br )? ● Ceil one-to-one INTEGER (rounded up) float ceil (f

I. mathematical functions library

● Floor

Rounding (rounding down)

Float floor (float $ value );

  ");echo(floor(0.40)."
");echo(floor(5)."
");echo(floor(5.1)."
");echo(floor(-5.1)."
");echo(floor(-5.9)."
")?>

● Ceil

One INTEGER (rounded up)

Float ceil (float $ value );

  ");echo(ceil(0.40)."
");echo(ceil(5)."
");echo(ceil(5.1)."
");echo(ceil(-5.1)."
");echo(ceil(-5.9)."
")?>

● Max

Maximum Value

Mixed max (mixed $ value, mixed $ value ,......);

  ");echo(max(-3,5)."
");echo(max(-3,-5)."
");echo(max(7.25,7.30)."
");?>

● Min

Minimum value

Mixed min (mixed $ value, mixed $ value ,......);

  ");echo(min(-3,5)."
");echo(min(-3,-5)."
");echo(min(7.25,7.30)."
");?>

● Pow

Power Operation

Number pow (number $ base, number $ expr );

  ";echo pow(6,2)."
";echo pow(-6,2)."
";echo pow(-6,-2)."
";echo pow(-6,5.5)."
";?>

● Sqrt

Take the square root

Float sqrt (float $ arg)

  ";echo(sqrt(1))."
";echo(sqrt(9))."
";echo(sqrt(0.64))."
";echo(sqrt(-9))."
";?>

● Rand

Generate random number

Int mt_rand (int $ min, int max );

  ";echo rand(10,100)."
";?>

● Mt_rand

Generate a better Random Number

Int mt_rand (int $ min, int max );

Similar to the preceding rand usage and output results, this is four times faster than rand.

● Round

Rounding

Float round (float $ val [, int $ precision = 0])

Optional; number of decimal places

●Number_format

Format a number using a thousand-bit grouping

Float number_format (float $ number, int $ decimals = 0, string $ dec_point = ',', string $ thousands_sep = ',');

Ii. Date and time function library

● Time

Returns the current Unix timestamp.

Int time (void );

  ";$nextWeek = time() + (7 * 24 * 60 * 60); // 7 days; 24 hours; 60 mins; 60secsecho 'Now:       '. date('Y-m-d') ."
";echo 'Next Week: '. date('Y-m-d', $nextWeek) ."
";?>

● Date

Format a local time/date

String date (string format [, int timestamp]);

● Getdate

Get date/time information

Array getdate ([int timestamp]);

● Microtime

Returns the current Unix Timestamp and the number of microseconds.

Mixed microtime ([bool get_as_float]);

●Date_default_timezone_set

Set Default Time Zone

Bool date_default_timezone_set (string timezone_identifier );

●Date_default_timezone_get

Get Default Time Zone

String date_default_timezone_get (void );

Iii. Character function library

Strlen

Returns the string length.

Int strlen (string $ str );

Strtolower

String to lowercase

String strtolower (string $ str );

Strtoupper

Convert string to uppercase

String strtoupper (string $ str );

Ucfirst

Uppercase letters

String ucfirst (string $ str );

Ucwords

Converts the first letter of each word to an uppercase letter.

String ucwords (string $ str );

Ltrim

Removes spaces or other characters from the start of a string.

String ltrim (string $ str [, string $ charlist]);

Rtrim

Removes spaces or other characters from the end of a string.

String rtrim (string $ str [, string $ chirlist]);

Trim

Removes spaces or other characters from the start and end of a string.

Str_replace

Character replacement

Mixed str_ireplace (mixed $ search, mixed $ replace, mixed $ subject, [int $ count]);

Str_ireplace

Character replacement

Mixed str_ireplace (mixed $ search, mixed $ replace, mixed $ subject, [int $ count]);

Md5

Calculate the MD5 hash of a string

String md5 (string $ str [, bool $ raw_output = false]);

Strpos

Returns the position where one character appears for the first time.

Int strpos (string haystack, mixed needle [, int offset]);