004 - PRE-DEFINED FUNCTIONS

• Strings

  • These are actually one-dimensional array of characters terminated by a null characters terminated by a null character ‘\0’.
• 80

  • The safest size option when the size of the array is unknown.
• strcpy (s1, s2);

  • Copies string s2 into string s1.
• strcat (s1, s2);

  • Concatenates string s2 onto the end of string s1.
• strlen (s1);

  • Returns the length of string s1.
• strcmp (s1, s2);

  • String comparison
  • Returns 0 if s1 and s2 are the same; less than 0 if s1 < s2; greater than 0 if s1 > s2.
• strchr (s1,s2);

  • Returns a substring of string beginning at the first occurrence of character c(count) up to the end of string.
• strrev(string)

  • Reverses all characters except the null terminator in the string.
• Power Function

  • The pow function is used to calculate the power of the base raised to the power of the exponent.
• Power Function

  • It accepts two double values as arguments which are the base and exponents numbers and it returns a single double integer which is base to the power of exponent.
• POWER FUNCTION SYNTAX

  • double pow(double, double)
• SQRT FUNCTION

  • Sqrt function in C++ returns the square root of the double integer inside the parameter list.
• SQRT FUNCTION SYNTAX

  • double sqrt(double)
• LOG FUNCTION

  • The log function is used to find the natural log of the given number.
  • This method accepts single double integer value finds logarithmic value and returns a double integer result of log()
• FLOOR FUNCTION

  • The floor function is used to return the floor value of the given double integer floor value means rounded down value.
• FLOOR FUNCTION SYNTAX

  • double floor(double)
• CEILING FUNCTION

  • The ceil function is used to return the ceil value of the given double integer.
  • Ceil value means rounded up value.
• CEILING FUNCTION SYNTAX

  • double ceil(double)
• ABSOLUTE VALUE FUNCTION

  • The abs function returns the absolute value of the integer value.
  • The function accepts an integer value and returns an integer value that has the same magnitude but positive sign.
• ABSOLUTE VALUE SYNTAX

  • double abs(double)
• int isalnum(int c)

  • This function checks whether the passed character is alphanumeric.
• int isalpha(int c)

  • This function checks whether the passed character is alphanumeric.
• int iscntrl(int c)

  • This function checks whether the passed character is control character.
• int isdigit(int c)

  • This function checks whether the passed character is decimal digit.
• int isgraph(int c)

  • This function checks whether the passed character has graphical representation using locale.
• int islower(int c)

  • This function checks whether the passed character is lowercase letter.
• int isprint(int c)

  • This function checks whether the passed character is printable.
• int ispunct(int c)

  • This function checks whether the passed character is a punctuation character.
• int isspace(int c)

  • This function checks whether the passed character is white-space.
• int isupper(int c)

  • This function checks whether the passed character is an uppercase letter.
• int isxdigit(int c)

  • This function checks whether the passed character is a hexadecimal digit.