Pascal Common functions

　　

Inc (I) make i:=i+1;

Inc (I,B) makes i:=i+b;

Dec (i) makes i:=i-1;

Dec (i,b) makes i:=i-b;

ABS (x) to find the absolute value of x: ABS (-3) =3

Chr (x) to find the character that corresponds to the number x. Example: CHR = ' a ' chr (+) = ' A ' chr (48) = ' 0 '

Ord (x) to find the number corresponding to the character X. Example: Ord (' a ') =65 ord (' a ') =97 in addition: Ord (false) =0 Ord (True) =1

SQR (x) asks for the square of X. Example: Sqr (4) =16

sqrt (x) asks for the root of X. Example: sqrt (16) =4

Round (x) Rounding example of x: Round (4.5) =5

Trunc (x) to find an integer part of x: Trunc (5.6) The =5 result is an integer type

int (x) to find an integer part of x int (5.6) =5.0 result is a real type

Frac (x) to find a small part of X frac (5.6) =0.6

Pred (x) to find the leading pred of X (' B ') = ' A ' pred (5) =4 pred (True) =false

SUCC (x) for the subsequent succ of X (' B ') = ' C ' succ (5) =6 succ (false) =true

Odd (x) determines whether x is an odd number. If the value is true, the inverse value is false. Odd (2) =false odd (5) =true

Power (A,n) asks for the N Power (2,3) of a =8 { can only be used when you open the math library }

Random number between 0~1 (cannot be taken to 1)

Randomize the seed function of a random number, the function is placed at the top of each set of random numbers.

Fillchar (A,size (a), 0) array initialization, that is, the value of array A is all set to 0 {The Boolean variable is also possible}

SHR:X SHR n convert x to binary and move N to the right, equivalent to dividing x by 2n

Shl:x SHL n turns x into binary and shifts the n position to the left, which is equivalent to multiplying x by 2n

1. The connection operation Concat (S1,S2,S3...SN) is equivalent to S1+S2+S3+...+SN.

Example: concat (' One ', ' aa ') = ' 11AA ';

2. Ask for a substring. Copy (s,i,l) intercepts the substring of length L after the beginning of the first character from the string s.

Example: Copy (' Abdag ', 2,3) = ' BDA '

3. Delete the substring. Procedure Delete (s,i,l) removes a substring of l after the start of the first character from the string s.

Example: s:= ' ABCDE ';d elete (s,2,3); results s:= ' AE '

4. Insert a substring. Procedure Insert (S1,s2,i) inserts the S1 into the first position of the S2

Example: S:=abc;insert (' n ', s,2); result s:= ' A12BC '

5. String length (s) Example: Length (' 12abc ') =5

6. Search for the location of the substring POS (S1,S2) If S1 is a substring of S2, returns the position of the first character of S1 in S2, or 0 if it is not a substring.

Example: POS (' ab ', ' 12ABCD ') =3

7. Uppercase conversions for characters. UpCase (CH) to find the uppercase body of the character Ch.

Example: UpCase (' a ') = ' a '

8. The numeric value is converted to a string. The process str (X,S) turns the value x into several strings of S.

Example: Str (12345,s); Results s= ' 12345 '

9. Number of strings converted to numeric values. The process Val (s,x,i) converts several strings of s into numerical X, and if successful it is i=0, unsuccessful then I is an ordinal of an invalid character

Example: Val (' 1234 ', x,i); result x:=1234

①: The pred (x) function value is x-l, for example:

Pred (6) =5 pred (-21) =-22

② successor function: The value of the SUCC (x) function is x+l, for example:

SUCC (L5) =16 SUCC (-114) = 113

③ Absolute Value function: the Abs (x) function values are ︱x︱, for example:

ABS ( -119) =119 ABS (101) =101

④ Square Function: The value of the SQR (x) function is X2, for example:

Sqr ( -5) =,25 sqr (l0) = 100

The result of the above four functions is still an integer number.

⑤ odd function: Odd (x), the result of the function is a Boolean type. When x is odd, the function value is true, and when X is even, the function value is false. For example:

Odd = True odd (+) = False

⑥ character function: Chr (X), the function value is the ASCII character of the ordinal, which is a character type. For example:

CHR = ' A ' chr (32) = '

Absolute function abs (x): The value of the function is the absolute number of X

Square function Sqr (x): The function value is the square of X

Decimal function Frac (x): Fractional part of the function value X

integer function int (x): function value is an integer part of X

sqrt (x) of the square root function: The value of the function is the square root of X

Stochastic function Random: When there is no argument, the function value takes a random number between (0,1), and when there is an independent variable and is a Word type, the function value takes a random integer between (0, the argument).

successor function SUCC (CH): For example, SUCC (' 8 ') = ' 9 ' Succ (' E ') = ' F '

The SUCC function has no meaning for the last character of the character set.

Pre-trend function Pred (CH): For example, Pred (' 7 ') = ' 6 ' Pred (' B ') = ' A '

ordinal function ord (CH):: Gives the ordinal of the character ch in the ASCII character set, the result is an integer type.

Ord (B) For example: Ord (False) =0 Ord (True) =1

Pascal Common functions