With numeric values in a gt table, we can perform currency-based formatting. This function supports both automatic formatting with a three-letter currency code and numeric formatting facilitated through the use of a locale ID. For fine control the conversion from numeric to currency values, we can take advantage of the following options:

• the currency: providing a currency code or common currency name will procure the correct currency symbol and number of currency subunits

• currency symbol placement: the currency symbol can be placed before or after the values

• decimals/subunits: choice of the number of decimal places, and a choice of the decimal symbol, and an option on whether to include or exclude the currency subunits (decimal portion)

• negative values: choice of a negative sign or parentheses for values less than zero

• digit grouping separators: options to enable/disable digit separators and provide a choice of separator symbol

• scaling: we can choose to scale targeted values by a multiplier value

• pattern: option to use a text pattern for decoration of the formatted currency values

• locale-based formatting: providing a locale ID will result in currency formatting specific to the chosen locale

fmt_currency(data, columns, rows = NULL, currency = "USD",
use_subunits = TRUE, negative_val = "signed", decimals = NULL,
use_seps = TRUE, scale_by = 1, pattern = "{x}", sep_mark = ",",
dec_mark = ".", placement = "left", incl_space = FALSE,
locale = NULL)

## Arguments

data a table object that is created using the gt() function. the columns to format. Can either be a series of column names provided in vars(), a vector of column indices, or a helper function focused on selections. The select helper functions are: starts_with(), ends_with(), contains(), matches(), one_of(), and everything(). optional rows to format. Not providing any value results in all rows in columns being formatted. Can either be a vector of row captions provided c(), a vector of row indices, or a helper function focused on selections. The select helper functions are: starts_with(), ends_with(), contains(), matches(), one_of(), and everything(). We can also use expressions to filter down to the rows we need (e.g., [colname_1] > 100 & [colname_2] < 50). the currency to use for the numeric value. This input can be supplied as a 3-letter currency code (e.g., "USD" for U.S. Dollars, "EUR" for the Euro currency). Use info_currencies() to get an information table with all of the valid currency codes and examples of each. Alternatively, we can provide a common currency name (e.g., "dollar", "pound", "yen", etc.) to simplify the process. Use info_currencies() with the type == "symbol" option to view an information table with all of the supported currency symbol names along with examples. If nothing is provided then "USD" will be used. an option for whether the subunits portion of a currency value should be displayed. the formatting to use for negative values. With signed (the default), negative values will be shown with a negative sign. Using parens will show the negative value in parentheses. an option to specify the exact number of decimal places to use. The default number of decimal places is 2. an option to use digit group separators. The type of digit group separator is set by sep_mark and overridden if a locale ID is provided to locale. This setting is TRUE by default. a value to scale the input. The default is 1.0. a formatting pattern that allows for decoration of the formatted value. The value itself is represented by {x} and all other characters are taken to be string literals. the mark to use as a separator between groups of digits (e.g., using sep_mark = "," with 1000 would result in a formatted value of 1,000). the character to use as a decimal mark (e.g., using dec_mark = "," with 0.152 would result in a formatted value of 0,152). the placement of the currency symbol. This can be either be left (the default) or right. an option on whether to include a space between the value and the currency symbol. The default is to not introduce a space character. an optional locale ID that can be used for formatting the value according the locale's rules. Examples include "en_US" for English (United States) and "fr_FR" for French (France). The use of a valid locale ID will override any values provided in sep_mark and dec_mark.

## Value

an object of class gt_tbl.

## Details

We can use the info_currencies() function for a useful reference on all of the possible inputs to currency.

Targeting of values is done through columns and additionally by rows (if nothing is provided for rows then entire columns are selected). A number of helper functions exist to make targeting more effective. Conditional formatting is possible by providing a conditional expression to the rows argument. See the Arguments section for more information on this.

## Figures

Other data formatting functions: data_color, fmt_datetime, fmt_date, fmt_missing, fmt_number, fmt_passthrough, fmt_percent, fmt_scientific, fmt_time, fmt, text_transform

## Examples

# Use exibble to create a gt table;
# format the currency column to have
# currency values in euros (EUR)
tab_1 <-
exibble %>%
gt() %>%
fmt_currency(
columns = vars(currency),
currency = "EUR"
)

# Use exibble to create a gt table;
# Keep only the num and currency,
# columns, then, format those columns
# using the "CNY" and "GBP" currencies
tab_2 <-
exibble %>%
dplyr::select(num, currency) %>%
gt() %>%
fmt_currency(
columns = vars(num),
currency = "CNY"
) %>%
fmt_currency(
columns = vars(currency),
currency = "GBP"
)