Programming Gambas from Zip/Functions

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Functions Reference[edit]

String Functions[edit]

Character Codes
Asc Returns the ASCII code of a character Every character has an ASCII code, eg Asc("A") is 65.
Chr Returns a character from its ASCII code Chr(65) is "A" . Chr(32) is the space. Chr(1) is Ctrl-A

When checking to see if a key was pressed, use Key["A"] or Key[Key.ShiftKey] instead for the number of a key on the keyboard, rather than the number of a character.

Parts of Strings
Left The left-hand end of a string Left("Hello", 4) is "Hell"
Mid The “middle” part of a string

Mid(String, StartingAt, HowLong)

Mid("Gambas", 3, 2) is mb because that is the string that starts at position 3 and is 2 characters long.
Right The right-hand end of a string Right("String", 4) is "ring"
Find and Replace
InStr The position of the second string in the first

InStr(String, LookFor)

InStr(String, LookFor, StartingAt)

InStr("Gambas is basic", "bas") is 4, because bas starts at position 4.

InStr("Gambas is basic", "bas", 6) is 11, because InStr only starts looking for bas from position 6.

If the string is not found it returns 0.

InStr("Gambas is basic", "bas", -5) is 11. The -5 means only start looking five from the end until the end, i.e. at position 10, the second space. Note that the last letter, c, is not 1 from the end. It is the end. i is 1 from the end.

Replace The string with every occurrence of something replaced by something else

Replace(String, LookFor, WithThis)

Replace("Abracadabra", "a", "*") is Abr*c*d*br*

Message( Replace(LetterText, "<name>", FirstName&" "&LastName) )

Subst A string with its markers replaced by other strings Subst("Tell &1 to arrive at &2 PM", "Mark", "4") is

"Tell Mark to arrive at 4 PM"

Change Case
UCase Converts a string to uppercase. UCase("gerard") is "GERARD"
LCase The string converted to lower case LCase("GERARD") is "gerard"
Trimming
Trim A string with no spaces at either end Trim(" Hello ") is "Hello"
LTrim Left Trim

The string with spaces removed from the start

LTrim(" Hello") is "Hello"
RTrim Right Trim

The string with spaces removed from the end

RTrim("Hello ") is "Hello"
Building Strings
String A string made of the same string repeated many times.

String(HowMany, WhichString)

String(6, "*") is "******"

String(2, "Gambas") is "GambasGambas"

Space A string of spaces Space(8) is eight spaces
Quote The string in quotation marks

The UnQuote function removes them.

Quote("Hello,") & " she said." is "Hello," she said.
Miscellaneous
Len The length of a string Len("Gambas is basic") is 15
Comp Compares two strings

Comp(FirstString, SecondString)

Comp(FirstString, SecondString, Mode)

If the two strings are the same, it returns 0.

If the first string comes after the second in a dictionary, it returns +1

If the first string comes before the second it is -1

If Comp(UserName, "Akiti", gb.IgnoreCase) = 0 Then Message("Welcome Akiti!") else Message("You’re not Akiti!")

Split An array made from a string

Split(String, Separator)

Dim z As String[] = Split("John,Mary,Paul,Gemma,Lucille,Hamish", ",")

The string is split at the commas.

Numeric Functions[edit]

Positives and Negatives
Abs Absolute value of a number — remove the negative sign if any. Abs(7) = 7

Abs(-7) = 7

Sgn Sign (+, 0, –) of a number Sign(3.14) = +1

Sign(–6) = –1

Sign(0) = 0

To Whole Numbers
Int Integer part of a number

Negative numbers are rounded down; positive numbers abandon the fraction part.

Int(3.2) = 3

Int(3.9) = 3

Int(6) = 6

Int(-7.2) = -8

Int(-7.9) = -8

Round Round a number to the nearest integer or power of ten

e.g. 10^2 is 100, so Round(x,2) is to the nearest 100.

Negative powers are how many decimal places

Round(Pi, -2) = 3.14

Print Round(1972, 2) = 2000

Frac The fractional part of a number

The fractional part of a date is the time.

Frac(3.14) = 0.14

Frac(Date(1999, 12, 13, 14, 20, 00)) = 0.597222222015

CDate(Frac(Date(1999, 12, 13, 14, 20, 00))) = 14:20:00

Fix Integer part of a number—remove any fractional part Fix(3.14) = 3

Fix(-3.14) = -3

CInt Convert to an integer

Abandon the fraction part completely.

Int(3.2) = 3

Int(3.9) = 3

Int(6) = 6

Int(-7.2) = -7

Int(-7.9) = -7

Floor Round down to the next lowest whole number Floor(3.14) = 3

Floor(-3.14) = -4

Ceil Ceiling: round up to the next highest whole number Ceil(3.14) = 4

Ceil(-3.14) = 3

Comparing
Max Whichever of two numbers is greater

Also works with dates

Max(6,4) = 6
Min Whichever of two numbers is lesser

Also works with dates

Min(6,4) = 4
Increment and Decrement
INC Increments a variable; same as x += 1 or x = x+1

This is an procedure rather than a function (no brackets; it’s a verb, not a noun)

INC x
DEC Decrement a variable; same as x –= 1 or x = x–1

This is an procedure rather than a function.

DEC x

Character Test Functions[edit]

The empty string is NULL. IsNull("") is True. IsNull("M") is False.

IsAscii Tests if a string contains only ASCII characters.
IsBlank Tests if a string contains only blank characters.
IsDigit Tests if a string contains only digits.
IsHexa Tests if a string contains only hexadecimal digits.
IsLCase Tests if a string contains only lowercase letters.
IsLetter Tests if a string contains only letters.
IsPunct Tests if a string contains only printable non-alphanumeric characters.
IsSpace Tests if a string contains only space characters.
IsUCase Tests if a string contains only uppercase letters.

Random Numbers[edit]

Randomize Without it you get the same series of random numbers each time your program is run. Randomize

Just the word by itself.

Rand A random integer between two numbers. Rand(1,6) is a random number between 1 and 6 inclusively. This could be a dice throw.

Rand(1,2) is either a 1 or a 2.

Rnd A random floating point number. Rnd( ) is between 0 and 1

Rnd(9) is between 0 and 9, but never 9 itself.

Rnd(10, 20) is between 10 and 20, but never 20.

Time And Date[edit]

A given date and time is stored internally as two integers, the first being the date and the second being the time. The following examples may explain what you can do with dates and times.

Examples:

Now 07/08/2019 19:18:54.929 8 July 2019, almost 8:19 pm

The current date and time

Format(Now, "dddd dd/mm/yyyy hh:nn:ss") Tuesday 09/07/2019 20:45:13 More on Format() later. Use it to present a date and/or time, or indeed any number, in the way you want. And it is now 8:46pm on July 9, by the way.
Date() 07/07/2019 23:00:00 When today started, less one hour for Daylight Saving Time.
Date(1955, 6, 1) 05/31/1955 23:00:00 Someone’s birthday, less one hour for Daylight Saving Time. The date is assembled from Year, Month, Day.
Date(2019, 12, 25, 6, 15, 0) 12/25/2019 05:15:00 6:15 am on Christmas Day, 2019. Time for opening Christmas presents.

Year, Month, Day, Hours, Minutes, Seconds

DateAdd(Date(1955, 6, 1), gb.Day, 14) 06/14/1955 23:00:00 14 days after 1 June 1955. DS again.

You can add other things besides days:

gb.Second, gb.Minute, gb.Hour,

gb.Day, gb.Week, gb.WeekDay (ignore Saturday and Sunday),

gb.Month, gb.Quarter, gb.Year

DateDiff(Date(2019, 7, 6), Date(Now), gb.Day) 2 Days between two days ago and now
DateDiff(Date(Now), Date(2018, 12, 25), gb.Day) 195 How many days since Christmas?

(It’s now 2019. Last Xmas was 2018.)

DateDiff(RecentDate, PastDate, Units)

DateDiff(Date(Now), Date(2019, 12, 25), gb.Day) 170 How many days until Christmas?

(It’s now 2019.)

DateDiff(Date(1955, 6, 1), Now, gb.Second) 2022959392 How many seconds I have been alive
DateDiff(Date(1955, 6, 1), Now, gb.Day) 23413 How many days I have been alive
CLong(DateDiff(Date(1955, 6, 1), Now, gb.Minute)) * 72 2427551928 … no, wait, it’s 2427552144 … no, wait, it’s 2427552216 ... How many heartbeats since my birth.

Had to convert the DateDiff to Long Integer because without it there is an overflow problem: it shows as a negative number. Longs can hold very big numbers.

Parts of Dates and Times
Hour(Now) & " hrs " & Minute(Now) & " mins" 14 hrs 39 mins It is now 2:39 pm.

You can also use these:

Day(), Hour(), Minute(), Month()

Second(), Time(), Week(), Weekday()

Year()

"Rip van Winkle, this is " & Year(Now) Rip van Winkle, this is 2019 The year part of a date
WeekDay(Now) 2 0 = Sunday, 6 = Saturday

2 means it is Tuesday.

If WeekDay(Now) = gb.Tuesday then label1.text = "It is Tuesday." else label1.text = "It is not Tuesday." It is Tuesday. gb.Tuesday is a constant whose value is 2. Using the constant means you need not remember Tuesday is 2.

Others are gb.Monday, gb.Wednesday, gb.Thursday, gb.Friday, gb.Saturday and gb.Sunday

Time(Now) 14:58:44.654 The time part of a date (Now is the current date and time)
Time(14, 08, 25) 14:08:25 Assemble a time from its parts

Time(Hour, Minutes, Seconds)

Time() 15:05:09.515 The time right now
Conversions
Val("1/6/55") 05/31/1955 23:00:00 Converts the string to a date

The 1-hour difference is due to daylight saving time.

Val("1/6/55 2:00") 06/01/1955 01:00:00 2 am on 1 June 1955

The 1-hour difference is due to daylight saving time.

Val("1-6-55 2:00") nothing Very sensitive to the format… ignored
Str(2484515) 2484515 If you supply a number, Str() will convert that number to a string.
Dim D As Date = 2484515

label1.text = Str(D)

16/05/2002 01:00:00 The number has changed to a date.

Str() converts it into local date format

Dim D As Date = 2484515

label1.text = D

05/16/2002 United States date format
CDate("1-6-55 2:00") Error “Wanted date, got string instead”

Not only sensitive, but offended...

Programming Gambas from Zip
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