C # class

String class

(small blackboard hand without brackets small square brackets)

String. Length after length without parentheses output int type character Segment bytes

String. TrimStart ()-Remove the front space
String. TrimEnd ()-Remove the trailing space string. Trim ()-Remove the trailing space string

String. ToUpper ()-Capitalize lowercase letters in a string
String. ToLower ()-Converts uppercase letters in a string into lowercase

String. SubString (a); -Intercept the string, a-the subscript to begin intercepting, including the characters corresponding to the subscript
String. SubString (A, b); -A-starting from the first few subscripts, B-to intercept several characters

Used to intercept the ID must be within the index range or the program will crash unexpectedly

. IndexOf ("string"); -Returns the index of the first occurrence in the string, if no match is returned-1 finds the first index of the string that corresponds to the int type
int B = S.indexof ("string", S.indexof ("string") +1); Gets the second match, with the index of the second string being repeatedly found

String. LastIndexOf ("string"); -Returns the index of the last occurrence

String. Startwidth ("string"); -Determine whether to start with what
String. Endswidth ("string"); -Determine whether to end with what
String. Contains ("string"); -Determine if a string is included
S.replace (the string to replace, the replacement string); -Character substitution string
S.remove (3); -Remove all characters from index to end of string

Math Type

Math.pow (x, y); -to seek the Y-square of the second square x

MATH.SQRT (x); -square root radical under X

Math.ceiling (double); -Take the upper limit to marry a decimal of the maximum integer value 10.01=11

Math.floor (double); -Take the minimum value 10.1=10

Math.Round (double); 4 5 into when an integer is an odd number. 5 upper when Integer is even

=math.abs (double); -Take absolute value

DateTime class

DateTime Variable name = new DateTime (); -Define a variable time

DateTime.Now; -Get the current time of this PC

. ToString ("Format"); -Set date formatting, (year month months day)
yyyy-mm-month dd-day hh-12 hour HH-24 system hours mm-minutes ss-seconds ms-milliseconds

. AddYears (); -How many years are added on this time basis
. AddMonths (); -Increase Month
. AddDays (); -Increase Day
. AddHours (); -Increase hours
. AddMinutes (); -Add minutes
. AddSeconds (); -Add seconds

Adding time on the basis will automatically go up for example, plus 13 months will increase 1 years plus one months.

. year; -Gets the year of this time variable
. Month; -Get Month
. Day; -Day
. Hour; -Hour
. Minute; -Minute
. Second; -Seconds
. millisecond; -milliseconds alone to obtain this time of year and month day

. DayOfYear; -Get the current date is the day of the year such as February 5 is 36 days this year
. DayOfWeek; -Get the day of the week

TimeSpan type-time interval type
. Days-the difference in how many day
. Hours-How many hours the gap is in a day
. Minutes-How many minutes the gap in a day
. Seconds-How many seconds difference in a day
. Milliseconds-MS

. Total .... The cumulative gap is used to calculate the gap between month and day

C # class