[TOC] # 注释 ## 背景知识 1This is not completely true: there are a few minor breaking changes that don’t affect code on the web. These are detailed in [section D.1](http://people.mozilla.org/~jorendorff/es6-draft.html#sec-corrections-and-clarifications-with-possible-compatibility-impact) and [section E.1](http://people.mozilla.org/~jorendorff/es6-draft.html#sec-additions-and-changes-that-introduce-incompatibilities-with-prior-editions) of the ES6 specification.[↩](ch_about-es6.html#fnref-introduction_1) 2Source: Tweet by Allen Wirfs-Brock. https://twitter.com/awbjs/status/574649464687734785[↩](ch_faq.html#fnref-faq_1) ## 数据 1\[Speaking JS\] `parseFloat()` in ([“Speaking JavaScript”](http://speakingjs.com/es5/ch11.html#parseFloat)).[↩](ch_numbers.html#fnref-numbers_1) 2\[Speaking JS\] `parseInt()` in ([“Speaking JavaScript”](http://speakingjs.com/es5/ch11.html#parseInt)).[↩](ch_numbers.html#fnref-numbers_2) 3\[Speaking JS\] The details of rounding errors are explained in [“Speaking JavaScript”](http://speakingjs.com/es5/ch11.html#rounding_errors).[↩](ch_numbers.html#fnref-numbers_3) 4Internally, JavaScript has [two zeros](http://speakingjs.com/es5/ch11.html#two_zeros). `Math.sign(-0)` produces the result `-0` and `Math.sign(+0)` produces the result `+0`.[↩](ch_numbers.html#fnref-numbers_4) 5Iterables are explained in [another chapter](ch_iteration.html#ch_iteration).[↩](ch_parameter-handling.html#fnref-parameter-handling_1) 6Explained in [the chapter on Arrays](ch_arrays.html#ch_arrays).[↩](ch_parameter-handling.html#fnref-parameter-handling_2) ## 模块化 1The exceptions are function expressions and object literals, which you have to put in parentheses, because they look like function declarations and code blocks.[↩](ch_arrow-functions.html#fnref-arrow_functions_1) 2\[Spec\] Sect. “[Imports](http://www.ecma-international.org/ecma-262/6.0/#sec-imports)” starts with grammar rules and continues with semantics.[↩](ch_modules.html#fnref-modules_1) 3\[Spec\] The specification method [`GetExportedNames()`](http://www.ecma-international.org/ecma-262/6.0/#sec-getexportednames) collects the exports of a module. In step (7.d.i), a check prevents other modules’ default exports from being re-exported.[↩](ch_modules.html#fnref-modules_2) 4\[Spec\] Sect. “[Exports](http://www.ecma-international.org/ecma-262/6.0/#sec-exports)” starts with grammar rules and continues with semantics.[↩](ch_modules.html#fnref-modules_3) ## 集合 1\[Speaking JS\] “[Pitfalls: Using an Object as a Map](http://speakingjs.com/es5/ch17.html#_pitfalls_using_an_object_as_a_map)”[↩](ch_iteration.html#fnref-iteration_1) 2Based on “[Closing iterators](https://github.com/rwaldron/tc39-notes/blob/master/es6/2014-06/closing-iterators.pdf)”, slides by David Herman.[↩](ch_iteration.html#fnref-iteration_2) 3`throw()` is also an optional method, but is practically never used for iterators and therefore explained in [the chapter on generators](ch_generators.html#ch_generators))[↩](ch_iteration.html#fnref-iteration_3) 4“[Combinator](https://wiki.haskell.org/Combinator)” (in HaskellWiki) describes what combinators are.[↩](ch_iteration.html#fnref-iteration_4) 5Or rather, the function counts up until the number `start` overflows and becomes `Infinity`, at which point it doesn’t change, anymore.[↩](ch_generators.html#fnref-generators_1)