Library Function in QBASIC

1. LEFT$:

LEFT$ is a string function that allows us to extract the specific number of characters beginning from the left-most character of the string.

2. RIGHT$:

RIGHT$ is a string function that allows us to extract the specific number o characters beginning from the right-most character of the string.

3. MID$:

MID$ function returns a specific number of characters from a string.

4. LEN:

LEN function returns the number of characters in a string or the number of bytes required by a variable.

5. LCASE$:

LCASE$ function converts all the uppercase characters in lowercase.

6. UCASE$:

UCASE$ function converts string to uppercase.

7. ASC:

ASC function converts a character or a string variable to its corresponding ASC II code. Only the first character of a string is evaluated by ASC function.

8. CHR$:

CHR$ function retrieves the single character represented by the ASC II number.

9. STR$:

STR$ function converts a string expression to its string representation.

10. VAL:

VAL function converts a string expression consisting of digits into numeric value.

11. LTRIM$:

LTRIM$ function removes leading blanks from the left side of the spring expression.               

12. RTRIM$:

RTRI$ function removes trailing blanks from the right side of the string expression .

13. STRING$:

STRING$ function is used with a PRINT statement to display a particular character a specific number of times.

14. INSTR:

INSTR function returns the position of the first occurrence of a string in another string.

15. DATE$:

DATE$ function returns the current system date of the computer and allow to set the current system date.

16. TIME$:

TIME$ function returns the current system time of computer and allows to set the current time.

17. INKEY$:

 INKEY$ function checks the keyboard looking for a pressed key.

18. INPUT$:

INPUT$ function halts execution until a specified number of characters are read from the keyboard or a disk file.

19. ABS:

ABS function is used to obtain the absolute value of a numeric expression.

20. COS:

COS function computes the cosign of an angle.

21. TAN:

TAN function is used to obtain the tangent of x.

22. SIN:

SIN function is used to obtain the sine o an angle.

23. INT:

INT function is used to round the number to the integer value.

24. CINT:

CINT function returns the nearest to the given number.

25. SGN:

SGN function returns the sign of a number.

26. SQR:

SQR function returns the square root  of a number.

27. TAB:

TAB function moves the text cursor to the specified print position.

28. SPC:

The SPC function skips a number of spaces when used with the PRINT and the LPRINT statement.

29. SPACE$:

The SPACE$ function is used to print a specific number of blank spaces.

30. LOCATE:

The LOCATE statement controls the cursor, placing it on the specific row and column on the screen.