Float

Provide utilities for JS float.

The special value "Not a Number". See NaN on MDN.

Tests if the given value is _NaN

Note that both _NaN = _NaN and _NaN == _NaN will return false. isNaN is therefore necessary to test for _NaN. Return true if the given value is _NaN, false otherwise. See isNaN on MDN.

Tests if the given value is finite. Return true if the given value is a finite number, false otherwise. See isFinite on MDN.

Examples

RESCRIPT
/* returns [false] */
Js.Float.isFinite(infinity)

/* returns [false] */
Js.Float.isFinite(neg_infinity)

/* returns [false] */
Js.Float.isFinite(Js.Float._NaN)

/* returns [true] */
Js.Float.isFinite(1234.)

Formats a float using exponential (scientific) notation. Return a string representing the given value in exponential notation. Raise RangeError if digits is not in the range [0, 20] (inclusive). See toExponential on MDN.

Examples

RESCRIPT
/* prints "7.71234e+1" */
Js.Float.toExponential(77.1234)->Js.log

/* prints "7.7e+1" */
Js.Float.toExponential(77.)->Js.log

Formats a float using exponential (scientific) notation. digits specifies how many digits should appear after the decimal point. The value must be in the range [0, 20] (inclusive). Return a string representing the given value in exponential notation. The output will be rounded or padded with zeroes if necessary. Raise RangeError if digits is not in the range [0, 20] (inclusive). See toExponential on MDN.

Examples

RESCRIPT
/* prints "7.71e+1" */
Js.Float.toExponentialWithPrecision(77.1234, ~digits=2)->Js.log

Formats a float using fixed point notation. Return a string representing the given value in fixed-point notation (usually). Raise RangeError if digits is not in the range [0, 20] (inclusive). See toFixed on MDN.

Examples

RESCRIPT
/* prints "12346" (note the rounding) */
Js.Float.toFixed(12345.6789)->Js.log

/* print "1.2e+21" */
Js.Float.toFixed(1.2e21)->Js.log

Formats a float using fixed point notation. digits specifies how many digits should appear after the decimal point. The value must be in the range [0, 20] (inclusive). Defaults to 0. Return a string representing the given value in fixed-point notation (usually). See toFixed on MDN.

The output will be rounded or padded with zeroes if necessary.

Raise RangeError if digits is not in the range [0, 20] (inclusive)

Examples

RESCRIPT
/* prints "12345.7" (note the rounding) */
Js.Float.toFixedWithPrecision(12345.6789, ~digits=1)->Js.log

/* prints "0.00" (note the added zeroes) */
Js.Float.toFixedWithPrecision(0., ~digits=2)->Js.log

Formats a float using some fairly arbitrary rules. Return a string representing the given value in fixed-point (usually). toPrecision differs from Js.Float.toFixed in that the former will format the number with full precision, while the latter will not output any digits after the decimal point. See toPrecision on MDN.

Raise RangeError if digits is not in the range accepted by this function (what do you mean "vague"?)

Examples

RESCRIPT
/* prints "12345.6789" */
Js.Float.toPrecision(12345.6789)->Js.log

/* print "1.2e+21" */
Js.Float.toPrecision(1.2e21)->Js.log

Formats a float using some fairly arbitrary rules. digits specifies how many digits should appear in total. The value must between 0 and some arbitrary number that's hopefully at least larger than 20 (for Node it's 21. Why? Who knows). See toPrecision on MDN.

Return a string representing the given value in fixed-point or scientific notation. The output will be rounded or padded with zeroes if necessary.

toPrecisionWithPrecision differs from toFixedWithPrecision in that the former will count all digits against the precision, while the latter will count only the digits after the decimal point. toPrecisionWithPrecision will also use scientific notation if the specified precision is less than the number for digits before the decimal point.

Raise RangeError if digits is not in the range accepted by this function (what do you mean "vague"?)

Examples

RESCRIPT
/* prints "1e+4" */
Js.Float.toPrecisionWithPrecision(12345.6789, ~digits=1)->Js.log

/* prints "0.0" */
Js.Float.toPrecisionWithPrecision(0., ~digits=2)->Js.log

Formats a float as a string. Return a string representing the given value in fixed-point (usually). See toString on MDN.

Examples

RESCRIPT
/* prints "12345.6789" */
Js.Float.toString(12345.6789)->Js.log

Formats a float as a string. radix specifies the radix base to use for the formatted number. The value must be in the range [2, 36] (inclusive). Return a string representing the given value in fixed-point (usually). See toString on MDN.

Raise RangeError if radix is not in the range [2, 36] (inclusive)

Examples

RESCRIPT
/* prints "110" */
Js.Float.toStringWithRadix(6., ~radix=2)->Js.log

/* prints "11.001000111101011100001010001111010111000010100011111" */
Js.Float.toStringWithRadix(3.14, ~radix=2)->Js.log

/* prints "deadbeef" */
Js.Float.toStringWithRadix(3735928559., ~radix=16)->Js.log

/* prints "3f.gez4w97ry0a18ymf6qadcxr" */
Js.Float.toStringWithRadix(123.456, ~radix=36)->Js.log

Parses the given string into a float using JavaScript semantics. Return the number as a float if successfully parsed, _NaN otherwise.

Examples

RESCRIPT
/* returns 123 */
Js.Float.fromString("123")

/* returns 12.3 */
Js.Float.fromString("12.3")

/* returns 0 */
Js.Float.fromString("")

/* returns 17 */
Js.Float.fromString("0x11")

/* returns 3 */
Js.Float.fromString("0b11")

/* returns 9 */
Js.Float.fromString("0o11")

/* returns [_NaN] */
Js.Float.fromString("hello")

/* returns [_NaN] */
Js.Float.fromString("100a")