High-level Programming Language (Pascal)

String Procedures

• val (<InStr>, <Num>, <ErrorCode>)
  • converts a <InStr> to its numeric equivalent
  • if the conversion is successful, <Num> is assigned this numeric value and the <ErrorCode>, is assigned the value 0
  • if the conversion is unsuccessful, <ErrorCode> is assigned the position of the first invalid character in the <InStr> and <Num> is set to 0
  • if <Num> is declared as an integer, the <InStr> will be converted into an integer
  • if <Num> is declared real, the <InStr> will be converted into real
  • <ErrorCode> must be declared as an integer
  • for example,
    
    

InStr	Data type of Num	Num	ErrorCode	Remarks
'153'	integer	153	0	Valid conversion
'153'	real	1.5300000000E+02	0	Valid conversion
'52.68'	real	5.2680000000E+01	0	Valid conversion
'52.68'	integer	0	3	Decimal point is invalid for Num being an integer
'7A12'	integer	0	2	First invalid character is A

• str (<Num>, <OutStr>)
  • converts a numeric value, <Num>, to its string representation and assigns this string value to <OutStr>
  • <OutStr> must be string data type
  • field descriptors can be included in the str procedure to specify the string format
  • str (<Num>:<w>:<d>, <OutStr>)
  • for example,

Num	Data type of Num	Procedure call	OutStr
135	integer	str (Num, OutString)	135
135.0	real	str (Num, OutString)	1.3500000000E+02
135.79	real	str (Num:8:3, OutString)	135.790
24.3432	real	str (Num:2:0, OutString)	24