Number.parseFloat() - JavaScript
the number.parsefloat() method parses an argument and returns a floating point number.
... polyfill if (number.parsefloat === undefined) { number.parsefloat = parsefloat; } examples number.parsefloat vs parsefloat this method has the same functionality as the global parsefloat() function: number.parsefloat === parsefloat; // true this method is also part of ecmascript 2015.
... (its purpose is modularization of globals.) see parsefloat() for more detail and examples.

parseFloat() - JavaScript
the parsefloat() function parses an argument (converting it to a string first if needed) and returns a floating point number.

A re-introduction to JavaScript (JS tutorial) - JavaScript
if you want to convert a binary number to an integer, just change the base: parseint('11', 2); // 3 similarly, you can parse floating point numbers using the built-in parsefloat() function.
... unlike its parseint() cousin, parsefloat() always uses base 10.
...an + 5; // nan you can test for nan using the built-in isnan() function: isnan(nan); // true javascript also has the special values infinity and -infinity: 1 / 0; // infinity -1 / 0; // -infinity you can test for infinity, -infinity and nan values using the built-in isfinite() function: isfinite(1 / 0); // false isfinite(-infinity); // false isfinite(nan); // false the parseint() and parsefloat() functions parse a string until they reach a character that isn't valid for the specified number format, then return the number parsed up to that point.

Numbers and dates - JavaScript
between 1 and the smallest value greater than 1 that can be represented as a number (2.220446049250313e-16) number.min_safe_integer minimum safe integer in javascript (−253 + 1, or −9007199254740991) number.max_safe_integer maximum safe integer in javascript (+253 − 1, or +9007199254740991) methods of number method description number.parsefloat() parses a string argument and returns a floating point number.
... same as the global parsefloat() function.

New in JavaScript 1.1 - Archive of obsolete content
isnan() now works on every platform (not only unix anymore) parsefloat() and parseint() now return nan on all platforms, if the first character of the specified string cannot be converted to a number; in previous releases, it returned nan on solaris and irix and zero on all other platforms.

ECMAScript 2015 support in Mozilla - Archive of obsolete content
math.fround() (firefox 26) math.log10(), math.log2(), math.log1p(), math.expm1(), math.cosh(), math.sinh(), math.tanh(), math.acosh(), math.asinh(), math.atanh(), math.hypot(), math.trunc(), math.sign(), math.cbrt() (firefox 25) additions to the number object number.isnan() (firefox 16) number.isfinite() (firefox 16) number.isinteger() (firefox 16) number.parseint() (firefox 25) number.parsefloat() (firefox 25) number.epsilon (firefox 25) number.max_safe_integer, number.min_safe_integer (firefox 31) number.issafeinteger() (firefox 32) additions to the object object object.prototype.__proto__ has been standardized object.is() (firefox 22) object.setprototypeof() (firefox 31) object.assign() (firefox 34) object.getownpropertysymbols() (firefox 33) additions to the date object ...

Element.clientTop - Web APIs
(actually might be math.round(parsefloat()).) for example, if the computed "border-top-width" is zero, then clienttop is also zero.

Timing element visibility with the Intersection Observer API - Web APIs
note the use of parsefloat() here; because these values are strings, javascript tries to do a string concatenation instead of addition without it.

Functions - JavaScript
parsefloat() the parsefloat() function parses a string argument and returns a floating point number.

Grammar and types - JavaScript
parseint() parsefloat() parseint only returns whole numbers, so its use is diminished for decimals.

Number - JavaScript
number.parsefloat(string) this is the same as the global parsefloat() function.

Standard built-in objects - JavaScript
eval() uneval() isfinite() isnan() parsefloat() parseint() encodeuri() encodeuricomponent() decodeuri() decodeuricomponent() deprecated escape() unescape() fundamental objects these are the fundamental, basic objects upon which all other objects are based.

JavaScript reference - JavaScript
value properties infinity nan undefined globalthis function properties eval() isfinite() isnan() parsefloat() parseint() decodeuri() decodeuricomponent() encodeuri() encodeuricomponent() fundamental objects object function boolean symbol error objects error aggregateerror evalerror internalerror rangeerror referenceerror syntaxerror typeerror urierror numbers & dates number bigint math date text processing string regexp indexed collections array int8array ui...