Format

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Format () is an ambivalent primitive function which formats the right argument into a simple character array, optionally following the specification supplied as the left argument. The usage of the left argument varies across implementations.

Examples

Monadic form

Format in its monadic form allows the user to convert arrays of any type into simple character arrays (for example for concatenation with other character arrays). The result usually matches the interpreter's default display, either by or by REPL.

      supper  10
      'I ate ',(supper),' shrimp.'
I ate 10 shrimp.

      DATA(3) (2 2⍴⍳4) 'TEXT' 100
 1 2 3   1 2   TEXT 100
         3 4
      DATA
 1 2 3   1 2   TEXT 100
         3 4
      (DATA) (⍴⍕DATA)
 4  2 22

Dyadic form

The dyadic form of Format varies across implementations.

Dyalog APL and NARS2000 support column width and the number of decimal places for formatting numeric arrays. The following example formats the 2-by-3 array with 12 spaces per column, rounded to 2 decimal places:

      C2 3 32.10958 0 ¯101.4914 ¯99.40878 ¯101.872 1001.48173
 32.10958    0     ¯101.4914 
¯99.40878 ¯101.872 1001.48173
      C
2 3

      12 2C
       32.11        0.00     ¯101.49
      ¯99.41     ¯101.87     1001.48
      (12 2C)
2 36
Works in: Dyalog APL, NARS2000

APLX supports Format by example, which uses string left argument for a rich set of format specifications:

      '55.55' 22.234 1.398 11.00
22.23 1.4 11
      '55.55 5.555 55.55 55'22.234 1.398 0.00 11.0
22.23 1.398       11
      '555,555,555.55'1234567.89
  1,234,567.89
Works in: APLX

See also

External links

Tutorials

Documentation


APL built-ins [edit]
Primitive functions
Scalar
Monadic ConjugateNegateSignumReciprocalMagnitudeExponentialNatural LogarithmFloorCeilingFactorialNotPi TimesRollTypeImaginarySquare Root
Dyadic AddSubtractTimesDivideResiduePowerLogarithmMinimumMaximumBinomialComparison functionsBoolean functions (And, Or, Nand, Nor) ∙ GCDLCMCircularComplexRoot
Non-Scalar
Structural ShapeReshapeTallyDepthRavelEnlistTableCatenateReverseRotateTransposeRazeMixSplitEncloseNestCut (K)PairLinkPartitioned EnclosePartition
Selection FirstPickTakeDropUniqueIdentitySelectReplicateExpandSet functions (IntersectionUnionWithout) ∙ Bracket indexingIndex
Selector Index generatorGradeIndex OfInterval IndexIndicesDeal
Computational MatchNot MatchMembershipFindNub SieveEncodeDecodeMatrix InverseMatrix DivideFormatExecuteMaterialiseRange
Primitive operators Monadic EachCommuteConstantReplicateExpandReduceWindowed ReduceScanOuter ProductKeyI-beamSpawnFunction axis
Dyadic BindCompositions (Compose, Reverse Compose, Beside, Atop, Over) ∙ Inner ProductPowerAtUnderRankDepthVariantStencilCut (J)
Quad names
Arrays Index originMigration levelAtomic vector
Functions Case convertUnicode convert
Operators SearchReplace