Textfile  Input and Output  137  6. If e  has type Char, the default value of  w  is 1. Therefore  Write (F, C)  stands for begin  ft:  =  c;  Put  (F)  end.  7.  If  e  has type Integer, the default value of  w  is implemen­ tation defined. If  w  is  less than the number of characters  needed to write the integer, the entire representation of the  integer (including a' -'  if e  is negative) is written anyway!  8.  If  e  has a string type, the default value of  w  is the length of  the string.  If w  is less than this length, then only the first  w  characters of e  are written.  9.  If e  has  type  Boolean, the  default  value  of  w  is  implementation  defined.  One  of the  strings  'true'  or  'false'  is written according to 8. above depending on the  value  of w.  Whether upper-case or lower-case (or even  mixed-case) letters are written to represent the values  true  or false is implementation defined.  10.  If  e  has  type  Real,  the  default  value  of  w  IS  implementation-defined.  If w  is less than the number of  characters needed to write the real number, more space is  taken (including room for a '-'  if e  is negative). If  f  (the  fraction length) is specified, the value of e  will be written in  fixed-point  notation. Otherwise the value is written in decimal  floating-point  form using exponent notation.  The general form for fixed-point notation is the sequence of  characters: an optional minus sign (if the number is negative),  a  digit  sequence  representing  the  integer  part,  a  period  (decimal point), and a digit sequence representing the fraction  part. The length of the fraction part is specified by  f.  The general form for floating-point form is the sequence of  w  characters: a blank or minus sign, one digit, a period (decimal  point), a digit sequence, the letter  E  (or e), a plus sign or minus  sign, and a digit sequence having an implementation-defined  length representing the exponent. The length of the first digit  sequence (preceding the letter E) will vary depending on the  value of w. No additional preceding blanks are written for  decimal floating-point form.  Figure 12.b gives examples of formatted writes with each type. 