chore: fix typos

Signed-off-by: snoppy <michaleli@foxmail.com>

Author: xiaoxianBoy

get-started/ch1.md

@@ -246,7 +246,7 @@ The original snippet relied on `let` to create block-scoped `x` variables in bot
 
 | NOTE: |
 | :--- |
-| The `let` keyword was added in ES6 (in 2015). The preceding example of transpiling would only need to apply if an application needed to run in a pre-ES6 supporting JS environment. The example here is just for simplicity of illustration. When ES6 was new, the need for such a transpilation was quite prevalent, but in 2020 it's much less common to need to support pre-ES6 environments. The "target" used for transpiliation is thus a sliding window that shifts upward only as decisions are made for a site/application to stop supporting some old browser/engine. |
+| The `let` keyword was added in ES6 (in 2015). The preceding example of transpiling would only need to apply if an application needed to run in a pre-ES6 supporting JS environment. The example here is just for simplicity of illustration. When ES6 was new, the need for such a transpilation was quite prevalent, but in 2020 it's much less common to need to support pre-ES6 environments. The "target" used for transpilation is thus a sliding window that shifts upward only as decisions are made for a site/application to stop supporting some old browser/engine. |
 
 You may wonder: why go to the trouble of using a tool to convert from a newer syntax version to an older one? Couldn't we just write the two variables and skip using the `let` keyword? The reason is, it's strongly recommended that developers use the latest version of JS so that their code is clean and communicates its ideas most effectively.
 

objects-classes/ch2.md

@@ -197,7 +197,7 @@ You might wonder why empty slots are so bad? One reason: there are APIs in JS, l
 
 I don't have much specifically to say about functions here, other than to point out that they are also sub-object-types. This means that in addition to being executable, they can also have named properties added to or accessed from them.
 
-Functions have two pre-defined properties you may find yourself interacting with, specifially for meta-programming purposes:
+Functions have two pre-defined properties you may find yourself interacting with, specifically for meta-programming purposes:
 
 ```js
 function help(opt1,opt2,...remainingOpts) {

scope-closures/apB.md

@@ -119,7 +119,7 @@ The downside here is that LRU is quite non-trivial in its own right. You'll want
 
 ## Closure (PART 2)
 
-In this exercise, we're going to again practive closure by defining a `toggle(..)` utility that gives us a value toggler.
+In this exercise, we're going to again practice closure by defining a `toggle(..)` utility that gives us a value toggler.
 
 You will pass one or more values (as arguments) into `toggle(..)`, and get back a function. That returned function will alternate/rotate between all the passed-in values in order, one at a time, as it's called repeatedly.
 

types-grammar/ch2.md

@@ -608,7 +608,7 @@ greeting;                               // Hello!
 
 ### Static `String` Helpers
 
-The following string utility functions are proviced directly on the `String` object, rather than as methods on individual string values:
+The following string utility functions are provided directly on the `String` object, rather than as methods on individual string values:
 
 * `String.fromCharCode(..)` / `String.fromCodePoint(..)`: produce a string from one or more arguments representing the code-units (`fromCharCode(..)`) or whole code-points (`fromCodePoint(..)`)
 
@@ -988,7 +988,7 @@ Values of `bigint` type cannot have decimals, so the parsing is unambiguous that
 
 * `Number.isNaN(..)`: The bug-fixed version of the global `isNaN(..)` utility, which identifies if the argument provided is the special `NaN` value
 
-* `Number.parseFloat(..)` / `Number.parseInt(..)`: utilties to parse string values for numeric digits, left-to-right, until the end of the string or the first non-float (or non-integer) character is encountered
+* `Number.parseFloat(..)` / `Number.parseInt(..)`: utilities to parse string values for numeric digits, left-to-right, until the end of the string or the first non-float (or non-integer) character is encountered
 
 ### Static `Math` Namespace