The NumberFormatter class

(PHP 5 >= 5.3.0, PHP 7, PHP 8, PECL intl >= 1.0.0)

Introduction

Programs store and operate on numbers using a locale-independent binary representation. When displaying or printing a number it is converted to a locale-specific string. For example, the number 12345.67 is "12,345.67" in the US, "12 345,67" in France and "12.345,67" in Germany.

By invoking the methods provided by the NumberFormatter class, you can format numbers, currencies, and percentages according to the specified or default locale. NumberFormatter is locale-sensitive so you need to create a new NumberFormatter for each locale. NumberFormatter methods format primitive-type numbers, such as double and output the number as a locale-specific string.

For currencies you can use currency format type to create a formatter that returns a string with the formatted number and the appropriate currency sign. Of course, the NumberFormatter class is unaware of exchange rates so, the number output is the same regardless of the specified currency. This means that the same number has different monetary values depending on the currency locale. If the number is 9988776.65 the results will be:

  • 9 988 776,65 € in France
  • 9.988.776,65 € in Germany
  • $9,988,776.65 in the United States

In order to format percentages, create a locale-specific formatter with percentage format type. With this formatter, a decimal fraction such as 0.75 is displayed as 75%.

For more complex formatting, like spelled-out numbers, the rule-based number formatters are used.

Class synopsis

class NumberFormatter {
/* Constants */
public const int PATTERN_DECIMAL;
public const int DECIMAL;
public const int CURRENCY;
public const int PERCENT;
public const int SCIENTIFIC;
public const int SPELLOUT;
public const int ORDINAL;
public const int DURATION;
public const int PATTERN_RULEBASED;
public const int IGNORE;
public const int CURRENCY_ACCOUNTING;
public const int DEFAULT_STYLE;
public const int ROUND_CEILING;
public const int ROUND_FLOOR;
public const int ROUND_DOWN;
public const int ROUND_UP;
public const int ROUND_HALFEVEN;
public const int ROUND_HALFDOWN;
public const int ROUND_HALFUP;
public const int PAD_BEFORE_PREFIX;
public const int PAD_AFTER_PREFIX;
public const int PAD_BEFORE_SUFFIX;
public const int PAD_AFTER_SUFFIX;
public const int PARSE_INT_ONLY;
public const int GROUPING_USED;
public const int DECIMAL_ALWAYS_SHOWN;
public const int MAX_INTEGER_DIGITS;
public const int MIN_INTEGER_DIGITS;
public const int INTEGER_DIGITS;
public const int MAX_FRACTION_DIGITS;
public const int MIN_FRACTION_DIGITS;
public const int FRACTION_DIGITS;
public const int MULTIPLIER;
public const int GROUPING_SIZE;
public const int ROUNDING_MODE;
public const int ROUNDING_INCREMENT;
public const int FORMAT_WIDTH;
public const int PADDING_POSITION;
public const int SECONDARY_GROUPING_SIZE;
public const int SIGNIFICANT_DIGITS_USED;
public const int MIN_SIGNIFICANT_DIGITS;
public const int MAX_SIGNIFICANT_DIGITS;
public const int LENIENT_PARSE;
public const int POSITIVE_PREFIX;
public const int POSITIVE_SUFFIX;
public const int NEGATIVE_PREFIX;
public const int NEGATIVE_SUFFIX;
public const int PADDING_CHARACTER;
public const int CURRENCY_CODE;
public const int DEFAULT_RULESET;
public const int PUBLIC_RULESETS;
public const int DECIMAL_SEPARATOR_SYMBOL;
public const int GROUPING_SEPARATOR_SYMBOL;
public const int PATTERN_SEPARATOR_SYMBOL;
public const int PERCENT_SYMBOL;
public const int ZERO_DIGIT_SYMBOL;
public const int DIGIT_SYMBOL;
public const int MINUS_SIGN_SYMBOL;
public const int PLUS_SIGN_SYMBOL;
public const int CURRENCY_SYMBOL;
public const int INTL_CURRENCY_SYMBOL;
public const int MONETARY_SEPARATOR_SYMBOL;
public const int EXPONENTIAL_SYMBOL;
public const int PERMILL_SYMBOL;
public const int PAD_ESCAPE_SYMBOL;
public const int INFINITY_SYMBOL;
public const int NAN_SYMBOL;
public const int SIGNIFICANT_DIGIT_SYMBOL;
public const int TYPE_DEFAULT;
public const int TYPE_INT32;
public const int TYPE_INT64;
public const int TYPE_DOUBLE;
public const int TYPE_CURRENCY;
/* Methods */
public __construct(string $locale, int $style, ?string $pattern = null)
public static create(string $locale, int $style, ?string $pattern = null): ?NumberFormatter
public formatCurrency(float $amount, string $currency): string|false
public format(int|float $num, int $type = NumberFormatter::TYPE_DEFAULT): string|false
public getAttribute(int $attribute): int|float|false
public getErrorCode(): int
public getErrorMessage(): string
public getLocale(int $type = ULOC_ACTUAL_LOCALE): string|false
public getPattern(): string|false
public getSymbol(int $symbol): string|false
public getTextAttribute(int $attribute): string|false
public parseCurrency(string $string, string &$currency, int &$offset = null): float|false
public parse(string $string, int $type = NumberFormatter::TYPE_DOUBLE, int &$offset = null): int|float|false
public setAttribute(int $attribute, int|float $value): bool
public setPattern(string $pattern): bool
public setSymbol(int $symbol, string $value): bool
public setTextAttribute(int $attribute, string $value): bool
}

Predefined Constants

These styles are used by the numfmt_create() to define the type of the formatter.

NumberFormatter::PATTERN_DECIMAL
Decimal format defined by pattern
NumberFormatter::DECIMAL
Decimal format
NumberFormatter::CURRENCY
Currency format
NumberFormatter::PERCENT
Percent format
NumberFormatter::SCIENTIFIC
Scientific format
NumberFormatter::SPELLOUT
Spellout rule-based format
NumberFormatter::ORDINAL
Ordinal rule-based format
NumberFormatter::DURATION
Duration rule-based format
NumberFormatter::PATTERN_RULEBASED
Rule-based format defined by pattern
NumberFormatter::CURRENCY_ACCOUNTING
Currency format for accounting, e.g., ($3.00) for negative currency amount instead of -$3.00. Available as of PHP 7.4.1 and ICU 53.
NumberFormatter::DEFAULT_STYLE
Default format for the locale
NumberFormatter::IGNORE
Alias for PATTERN_DECIMAL

These constants define how the numbers are parsed or formatted. They should be used as arguments to numfmt_format() and numfmt_parse().

NumberFormatter::TYPE_DEFAULT
Derive the type from variable type
NumberFormatter::TYPE_INT32
Format/parse as 32-bit integer
NumberFormatter::TYPE_INT64
Format/parse as 64-bit integer
NumberFormatter::TYPE_DOUBLE
Format/parse as floating point value
NumberFormatter::TYPE_CURRENCY
Format/parse as currency value

Number format attribute used by numfmt_get_attribute() and numfmt_set_attribute().

NumberFormatter::PARSE_INT_ONLY
Parse integers only.
NumberFormatter::GROUPING_USED
Use grouping separator.
NumberFormatter::DECIMAL_ALWAYS_SHOWN
Always show decimal point.
NumberFormatter::MAX_INTEGER_DIGITS
Maximum integer digits.
NumberFormatter::MIN_INTEGER_DIGITS
Minimum integer digits.
NumberFormatter::INTEGER_DIGITS
Integer digits.
NumberFormatter::MAX_FRACTION_DIGITS
Maximum fraction digits.
NumberFormatter::MIN_FRACTION_DIGITS
Minimum fraction digits.
NumberFormatter::FRACTION_DIGITS
Fraction digits.
NumberFormatter::MULTIPLIER
Multiplier.
NumberFormatter::GROUPING_SIZE
Grouping size.
NumberFormatter::ROUNDING_MODE
Rounding Mode.
NumberFormatter::ROUNDING_INCREMENT
Rounding increment.
NumberFormatter::FORMAT_WIDTH
The width to which the output of format() is padded.
NumberFormatter::PADDING_POSITION
The position at which padding will take place. See pad position constants for possible argument values.
NumberFormatter::SECONDARY_GROUPING_SIZE
Secondary grouping size.
NumberFormatter::SIGNIFICANT_DIGITS_USED
Use significant digits.
NumberFormatter::MIN_SIGNIFICANT_DIGITS
Minimum significant digits.
NumberFormatter::MAX_SIGNIFICANT_DIGITS
Maximum significant digits.
NumberFormatter::LENIENT_PARSE
Lenient parse mode used by rule-based formats.

Number format text attribute used by numfmt_get_text_attribute() and numfmt_set_text_attribute().

NumberFormatter::POSITIVE_PREFIX
Positive prefix.
NumberFormatter::POSITIVE_SUFFIX
Positive suffix.
NumberFormatter::NEGATIVE_PREFIX
Negative prefix.
NumberFormatter::NEGATIVE_SUFFIX
Negative suffix.
NumberFormatter::PADDING_CHARACTER
The character used to pad to the format width.
NumberFormatter::CURRENCY_CODE
The ISO currency code.
NumberFormatter::DEFAULT_RULESET
The default rule set. This is only available with rule-based formatters.
NumberFormatter::PUBLIC_RULESETS
The public rule sets. This is only available with rule-based formatters. This is a read-only attribute. The public rulesets are returned as a single string, with each ruleset name delimited by ';' (semicolon).

Number format symbols used by numfmt_get_symbol() and numfmt_set_symbol().

NumberFormatter::DECIMAL_SEPARATOR_SYMBOL
The decimal separator.
NumberFormatter::GROUPING_SEPARATOR_SYMBOL
The grouping separator.
NumberFormatter::PATTERN_SEPARATOR_SYMBOL
The pattern separator.
NumberFormatter::PERCENT_SYMBOL
The percent sign.
NumberFormatter::ZERO_DIGIT_SYMBOL
Zero.
NumberFormatter::DIGIT_SYMBOL
Character representing a digit in the pattern.
NumberFormatter::MINUS_SIGN_SYMBOL
The minus sign.
NumberFormatter::PLUS_SIGN_SYMBOL
The plus sign.
NumberFormatter::CURRENCY_SYMBOL
The currency symbol.
NumberFormatter::INTL_CURRENCY_SYMBOL
The international currency symbol.
NumberFormatter::MONETARY_SEPARATOR_SYMBOL
The monetary separator.
NumberFormatter::EXPONENTIAL_SYMBOL
The exponential symbol.
NumberFormatter::PERMILL_SYMBOL
Per mill symbol.
NumberFormatter::PAD_ESCAPE_SYMBOL
Escape padding character.
NumberFormatter::INFINITY_SYMBOL
Infinity symbol.
NumberFormatter::NAN_SYMBOL
Not-a-number symbol.
NumberFormatter::SIGNIFICANT_DIGIT_SYMBOL
Significant digit symbol.
NumberFormatter::MONETARY_GROUPING_SEPARATOR_SYMBOL
The monetary grouping separator.

Rounding mode values used by numfmt_get_attribute() and numfmt_set_attribute() with NumberFormatter::ROUNDING_MODE attribute.

NumberFormatter::ROUND_CEILING
Rounding mode to round towards positive infinity.
NumberFormatter::ROUND_DOWN
Rounding mode to round towards zero.
NumberFormatter::ROUND_FLOOR
Rounding mode to round towards negative infinity.
NumberFormatter::ROUND_HALFDOWN
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down.
NumberFormatter::ROUND_HALFEVEN
Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor.
NumberFormatter::ROUND_HALFUP
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up.
NumberFormatter::ROUND_UP
Rounding mode to round away from zero.

Pad position values used by numfmt_get_attribute() and numfmt_set_attribute() with NumberFormatter::PADDING_POSITION attribute.

NumberFormatter::PAD_AFTER_PREFIX
Pad characters inserted after the prefix.
NumberFormatter::PAD_AFTER_SUFFIX
Pad characters inserted after the suffix.
NumberFormatter::PAD_BEFORE_PREFIX
Pad characters inserted before the prefix.
NumberFormatter::PAD_BEFORE_SUFFIX
Pad characters inserted before the suffix.

Table of Contents

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User Contributed Notes 7 notes

up
37
giorgio dot liscio at email dot it
11 years ago
this class seems to be painful: it is not, formatting and parsing are highly customizable, but what you probably need is really simple:

if you want to localize a number use:

<?php
$a
= new \NumberFormatter("it-IT", \NumberFormatter::DECIMAL);
echo
$a->format(12345.12345) . "<br>"; // outputs 12.345,12
$a->setAttribute(\NumberFormatter::MIN_FRACTION_DIGITS, 0);
$a->setAttribute(\NumberFormatter::MAX_FRACTION_DIGITS, 100); // by default some locales got max 2 fraction digits, that is probably not what you want
echo $a->format(12345.12345) . "<br>"; // outputs 12.345,12345
?>

if you want to print money use:

<?php
$a
= new \NumberFormatter("it-IT", \NumberFormatter::CURRENCY);
echo
$a->format(12345.12345) . "<br>"; // outputs €12.345,12
?>

if you have money data stored as (for example) US dollars and you want to print them using the it-IT notation, you need to use

<?php
$a
= new \NumberFormatter("it-IT", \NumberFormatter::CURRENCY);
echo
$a->formatCurrency(12345, "USD") . "<br>"; // outputs $ 12.345,00 and it is formatted using the italian notation (comma as decimal separator)
?>

another useful example about currency (how to obtain the currency name by a locale string):

<?php
$frontEndFormatter
= new \NumberFormatter("it-IT", \NumberFormatter::CURRENCY);
$adminFormatter = new \NumberFormatter("en-US", \NumberFormatter::CURRENCY);
$symbol = $adminFormatter->getSymbol(\NumberFormatter::INTL_CURRENCY_SYMBOL); // got USD
echo $frontEndFormatter->formatCurrency(12345.12345$symbol) . "<br>";
?>
up
1
stan at dragnev dot ca
2 years ago
Here's an example of how to use PATTERN_DECIMAL to print a number with two fraction digits, use () for negative numbers and pad to five characters to the left of the decimal point, using spaces as the padding character:

<?php

$fmt
= new NumberFormatter("en-CA", NumberFormatter::PATTERN_DECIMAL, "* #####.00 ;(* #####.00)");
echo
$fmt->format(-45.1);

// Outputs: "  (45.10)"

?>

Note that the ; in the pattern denotes the beginning of a subpattern, which is used for negative numbers. Hence the brackets around the pattern after the semicolon.
up
1
gwyneth dot llewelyn at gwynethllewelyn dot net
6 months ago
When using the `NumberFormatter` class for pretty-printing currency in PHP 7.3 and 8+, it's not clear from the documentation that you can use the empty string "" as the locale for the constructor, and that will retrieve the default locale (whatever it has been set to in your environment).

`formatCurrency()`, by contrast, does not accept the empty string for the default currency symbol; it will display a 'generic' currency symbol instead (¤).

Tested with PHP 7.4.30, 8.0.21, 8.1.8 under Ubuntu Linux and 8.1.8 under macOS Big Sur (11.6.8). I tried under other alternatives (e.g. Linux running on ARM chips, PHP 7.3.3) but sadly the `NumberFormatter` library does not seem to be present (or could not be found) on those systems...
up
1
sudheer at binaryvibes dot co dot in
12 years ago
Sample script to print number in English.

<?php
$f
= new NumberFormatter("en", NumberFormatter::SPELLOUT);
echo
$f->format(123456);

?>

Produces the result:
one hundred twenty-three thousand four hundred fifty-six
up
-1
Joey
5 years ago
Be warned that this class sometimes lacks sufficient error output. I recently instantiated it while invalid pattern to the constructor.

    php -r '$nf = new \NumberFormatter("tlh-KX.UTF8", \NumberFormatter::IGNORE, "{,,#;#}");var_dump($nf->format(5));'

    Fatal error: Call to a member function format() on null in Command line code on line 1

Rather than emitting an error message or throwing an exception null is returned after calling new.

I'm not sure if it's fixed in PHP 7 but it's something to watch out for. Make sure you check your parameters very closely.
up
-3
AF
2 years ago
Please pay attention to the Arabic decimal separator (https://en.wikipedia.org/wiki/Decimal_separator#Other_numeral_systems).

All the following conditions are true:
<?php
(new \NumberFormatter("ar_AE", \NumberFormatter::DEFAULT_STYLE))->getSymbol(\NumberFormatter::DECIMAL_SEPARATOR_SYMBOL) === '٫';
(new \
NumberFormatter("ar_AE", \NumberFormatter::DEFAULT_STYLE))->getSymbol(\NumberFormatter::DECIMAL_SEPARATOR_SYMBOL) == '٫';

(new \
NumberFormatter("ar_AE", \NumberFormatter::DEFAULT_STYLE))->getSymbol(\NumberFormatter::DECIMAL_SEPARATOR_SYMBOL) !== ',';
(new \
NumberFormatter("ar_AE", \NumberFormatter::DEFAULT_STYLE))->getSymbol(\NumberFormatter::DECIMAL_SEPARATOR_SYMBOL) != ',';
?>
up
-8
Adam
5 years ago
Good to know Numberformatter::SPELLOUT using soft hypens.

So, if you want to avoid it use preg_replace:

<?php
$azaz
= new NumberFormatter("hu-HU", NumberFormatter::SPELLOUT);
$text = preg_replace('~\x{00AD}~u', '', $azaz->format(123456));
print
$text;
?>
Output without preg_replace:
egy-­száz-­huszon-­három-­ezer négy-­száz-­ötven-­hat

Output with preg_replace:
egyszázhuszonháromezer négyszázötvenhat
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