GetDouble Method (JSONDATA)

10.8A, PLBCMP GUI Only

The GetDouble method gets the numeric value for a JSON field from a JSONDATA object and returns it as a user defined formatted string. The numeric value being returned is based on the type of value for the JSON field being accessed. This method uses the following format:

Where:

label

Optional. A Program Execution Label.

object

Required. A JSONDATA object previously declared.

return

Optional. A Character Variable that returns the output JSON value as a string with the format specified by the user input format. If an error occurs while retrieving the JSON value, the Character Variable is returned as a NULL variable.

name

Required. A Character String Variable or literal that specifies a JSON field name for a JSONDATA object.

format

Required. A Character String Variable or literal that specifies the format to be used for the return string.

index1

Optional. A Numeric Variable, decimal number, or Numeric expression that defines the first index of a JSON array that is being accessed.

index2

Optional. A Numeric Variable, decimal number, or Numeric expression that defines the second index of a JSON multi-dimensioned array that is being accessed.

index3

Optional. A Numeric Variable, decimal number, or Numeric expression that defines the third index of a JSON multi-dimensioned array that is being accessed.

Flags Affected: EOS, OVER, ZERO

Notes:

1. The EOS flag is set if the output JSON string is truncated because the {return} variable is too small.

2. The ZERO and OVER flags are always cleared.

3. At runtime, the tokens $1, $2, and $3 that appear in the {name} parameter are replaced with the numeric values of the corresponding {index1}, {index2}, or {index3} parameters.

4.  The {return} value that is returned as a formatted string is determined by the JSON field value type being accessed using a JSON field key specified by the {name} parameter. The JSON field value types are defined as follows:

 

Type	Return Value
$JSF_TYPE_OBJECT (1)	Returns the number of fields in the json object.
$JSF_TYPE_ARRAY (2)	Returns the number of elements in the array.
$JSF_TYPE_INTEGER (3)	Returns the field integer value.
$JSF_TYPE_DOUBLE (4)	Returns the whole digits value. Decimal digits are not returned.
$JSF_TYPE_STRING (5)	Returns the length of the JSON field string.
$JSF_TYPE_BOOLEAN (6)	Returns the value of one for a 'true' value. If the value is 'false', the return value is zero.
$JSF_TYPE_NULL (7)	Returns the value of zero.

 

5. The {format} string is the same as the common 'sprintf' formats used for a 'C' double value. The {format} string formats are described as follows:

 

Format	Output Style	Notes
%f	Fixed-point decimal	Default is 6 digits after decimal.
%.nf	Fixed-point decimal specifying number of decimal digits	The 'n' value specifies the number.of decimal digits. If the 'n' value is larger than 6, the output decimal digits can be indeterminate.    Example: ( %.2f )
%e or %E	Scientific notation	Lowercase 'e' vs uppercase 'E' for exponent.
%g or %G	Shortest representation (fixed or scientific)	Chooses between '%f' and '%e' depending on the magnitude, trims trailing zeros.

 

Here are some example 'GetDouble' outputs:

 

Format	Value	Output Returned
%f	12345.6789	12345.678900
%.2f	12345.6789	12345.68
%.10f	12345.6789	12345.6789000000
%e	12345.6789	1.2345678e+04
%.3e	12345.6789	1.235e+04
%.3E	12345.6789	1.235E+04
%g	312345.6789	312346
%.5g	312345.6789	3.1235e+05
%.5G	312345.6789	3.1235E+05

 

6. If an error occurs, the JSONDATA object method 'SyntaxError' canbe used to retrieve that last error that was generated.

Example:

.

     oJson JSONDATA

     .

     cFmt CONST "9"

     dFmtArr DIM 6(cFmt)

     dFmt INIT "%f;%.2f;%.10f;%e;%.3e;%.3E;%g;%.5g;%.5G"

     nFmtNdx FORM "0"

     dString DIM 65

     .

     names DIM 1024

     result FORM 10

     nameArr      DIM      25(cFmt)

     .

     jsonString init "{#"test1#":12345.6789,":

                         "#"test2#":12345.6789,":

                         "#"test3#":12345.6789,":

                         "#"test4#":12345.6789,":

                         "#"test5#":12345.6789,":

                         "#"test6#":12345.6789,":

                         "#"test7#":312345.6789,":

                         "#"test8#":312345.6789,":

                         "#"test9#":312345.6789}"

     .

              EXPLODE dFmt, ";", dFmtArr

     .

                 oJson.Parse Giving result Using *JSONDATA=jsonString

                 IF ( result != 0 )

                  DISPLAY "Error...Do 'oJson.SyntaxError'"

                  STOP

                 ENDIF

     .

                 oJson.GetNames Giving names Using names

     .

                 EXPLODE names, ",", nameArr

     .

                 FOR nFmtNdx, 1, cFmt

     .

                   oJson.GetDouble Giving dString:

                                   Using *Name=nameArr(nFmtNdx):

                                         *Format=dFmtArr(nFmtNdx)

     .

                   DISPLAY *LL, nameArr(nFmtNdx)," ==> ",dString

     .

                 REPEAT

     .

                 DISPLAY *W15

See Also: Method Syntax, JSONDATA Methods