| <Syntax> |
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FORMAT ( [ format-list ] [ infinite-repeat-item ] )
format-list ::= format-item [ , format-item ]...
| format-item | ::= | [ repeat ] data-edit |
| | | [ repeat ] ( format-list ) |
| | | other-edit |
infinite-repeat-item ::= * ( format-list )
| data-edit | ::= | iboz-edit w [ . m ] |
| | | fd-edit w [ . d ] |
| | | eg-edit w . d [ E e ] |
| | | L w |
| | | A [ w ] |
| | | G0 [ . d ] |
| other-edit | ::= | t-edit digit-string |
| | | digit-string px-edit |
| | | digit-stringHtext |
| | | character-string |
| | | rounding-edit |
| | | misc-edit |
repeat, w, m, d and e are all digit-string.
iboz-edit ::= I | B | O | Z
fd-edit ::= F | D
eg-edit ::= E | EN | ES | G
t-edit ::= T | TR | TL
px-edit ::= P | X | /
rounding-edit ::= RC | RD | RN | RP | RU | RZ
misc-edit ::= BN | BZ | DC | DP | S | SP | SS | / | :
In digit-stringHtext, the text following the H has exactly the number of characters specified by its digit-string; this edit descriptor was deleted in Fortran 95 because it is error-prone and less convenient than simply using a character string.
Note: the comma between adjacent format-items may be omitted only as follows:
between a P descriptor and a following D, E, EN, ES, F or G descriptor (prior to Fortran 2003, this is only allowed when the optional repeat is not present);
before a / descriptor that has no preceding digit-string;
after a / descriptor;
before or after a : descriptor.
The field width w is used to indicate minimal width editing for the B, F, I, O and Z edit descriptors.
In all other cases, w must be positive.
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| <Semantics> |
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The FORMAT statement specifies a format, which may be used in a data transfer statement (PRINT, READ and WRITE) for formatted input/output.
The FORMAT statement must be labelled, and it is this label that is specified in the FMT= specifier.
The interpretation of each edit descriptor is given in the table below.
Note that an explicit format may also be specified as a character string; in this case the character string is interpreted in the same way as the FORMAT statement.
Also, list-directed (FMT=*) and namelist formatting (NML=namelist-name) is possible instead of explicit formatting.
These two cases leave the formatting details up to the compiler and are not under user control.
In Fortran 2008, an infinite-repeat-item can appear at the end of the format specification.
As the name implies, this acts the same as an infinite repeat count — it repeats until terminated by exhaustion of the list of effective items on a colon or data edit descriptor; a data edit descriptor such as I must appear inside the infinite repetition.
| Format Item |
Semantics |
Example |
| Character string |
Output of specified character string |
'abc' |
| / |
Advance to next record |
/ |
| : |
Finish if no data items left in input list |
: |
| A |
Character type data transfer |
A10 |
| B |
Integer type data transfer, binary radix |
B8 |
| BN |
Blanks in numeric input are null (ignored) |
BN |
| BZ |
Blanks in numeric input are treated as zeros |
BZ |
| D |
Real type data transfer, exponential form with letter D |
D12.4 |
| DC |
Change decimal edit
mode to 'COMMA' |
DC |
| DP |
Change decimal edit
mode to 'POINT' |
DP |
| E |
Real type data transfer, exponential form |
E12.4 |
| EN |
Real type data transfer, engineering notation (exponent divisible by 3) |
EN12.4 |
| ES |
Real type data transfer, scientific notation (first digit non-zero) |
ES12.4 |
| F |
Real type data transfer, no exponent |
F6.3 |
| G |
Generalised data transfer, form varies |
G16.8 |
| G0 |
Generalised minimal width data transfer, form varies |
G0.7 |
| H |
Output of specified text |
nHa1a2...an |
| I |
Integer type data transfer, decimal radix |
I9 |
| L |
Logical type data transfer |
L1 |
| O |
Integer type data transfer, octal radix |
O3 |
| P |
Set scale factor to k |
kP |
| RC |
Compatible rounding (halves away from zero) |
RC |
| RD |
Round down (towards −∞) |
RC |
| RN |
Round to nearest (halves to even) |
RN |
| RP |
Processor-dependent rounding |
RP |
| RU |
Round up (towards +∞) |
RU |
| RZ |
Round towards zero |
RZ |
| S |
Processor-dependent “+” on positive values |
S |
| SP |
Produce “+” on positive values |
SP |
| SS |
Suppress “+” on positive values |
SS |
| T |
Move to position n in the current record |
T10 |
| TL |
Move n positions to the left in the current record |
T10 |
| TR |
Move n positions to the right in the current record |
TR10 |
| X |
Move right n places |
6X |
| Z |
Integer type data transfer, hexadecimal radix |
Z8 |
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| <Related> |
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ASSIGN statement,
BACKSPACE statement,
CLOSE statement,
DECIMAL= specifier,
ENDFILE statement,
NML= specifier,
OPEN statement,
PRINT statement,
READ statement,
REWIND statement,
SIGN= specifier,
WRITE statement |
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