prepend.md

Prepend To List (prepend)

Add data to the start of an array

Description

prepend a data to the start of an array.

Usage

<stdin> -> prepend: value -> <stdout>

Examples

» a [January..December] -> prepend: 'New Year'
New Year
January
February
March
April
May
June
July
August
September
October
November
December

Detail

prepend and append are data type aware:

» tout json [1,2,3] -> append 4 5 6 bob
Error in `append` (1,22): cannot convert 'bob' to a floating point number: strconv.ParseFloat: parsing "bob": invalid syntax

Synonyms

• prepend
• list.prepend

See Also

• Add Heading (addheading): Adds headings to a table
• Append To List (append): Add data to the end of an array
• Count (count): Count items in a map, list or array
• Create JSON Array (ja): A sophisticated yet simply way to build a JSON array
• Define Type (cast): Alters the data-type of the previous function without altering its output
• Get Item ([ Index ]): Outputs an element from an array, map or table
• Get Nested Element ([[ Element ]]): Outputs an element from a nested structure
• Match String (match): Match an exact value in an array
• Regex Operations (regexp): Regexp tools for arrays / lists of strings
• Reverse Array (mtac): Reverse the order of an array
• Sort Array (msort): Sorts an array - data type agnostic
• Stream New List (a): A sophisticated yet simple way to stream an array or list (mkarray)

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This document was generated from builtins/core/lists/append_doc.yaml.