js-array: update

js-array.md

@@ -1,67 +1,98 @@
 ---
-title: JavaScript arrays
+title: JavaScript Arrays
 category: JavaScript
+layout: 2017/sheet
 ---
 
-## JavaScript arrays
+### Arrays
 
-    array = [a,b,c,d,e]
+```bash
+list = [a,b,c,d,e]
+```
+{: .-setup}
 
-    array[1]                 //=> b
-    array.indexOf(b)         //=> 1
+```bash
+list[1]                 // → b
+list.indexOf(b)         // → 1
+```
 
 ### Subsets
 
-    array.slice(0,1)         //=> [a]
-    array.slice(1)           //=> [b,c,d,e]
-    array.slice(1,2)         //=> [b] 
+#### Immutable
 
-    // Destructive
-    re = array.splice(1)     // re = [b,c,d,e]     array == [a]
-    re = array.splice(1,2)   // re = [b,c]         array == [a,d,e]
+```bash
+list.slice(0,1)         // → [a        ]
+list.slice(1)           // → [  b,c,d,e]
+list.slice(1,2)         // → [  b      ]
+```
+
+#### Mutative
+
+```bash
+re = list.splice(1)     // re = [b,c,d,e]  list == [a]
+re = list.splice(1,2)   // re = [b,c]      list == [a,d,e]
+```
 
 ### Adding items
 
-    array.push(X)            // array == [_,_,_,_,_,X]
-    array.unshift(X)         // array == [X,_,_,_,_,_]
-    array.splice(2, 0, X)    // array == [_,_,X,_,_,_]
+#### Mutative
 
-    array.concat([X,Y])      //=> [_,_,_,_,_,X,Y]
+```bash
+list.push(X)            // list == [_,_,_,_,_,X]
+list.unshift(X)         // list == [X,_,_,_,_,_]
+list.splice(2, 0, X)    // list == [_,_,X,_,_,_]
+```
+
+#### Immutable
+
+```bash
+list.concat([X,Y])      // → [_,_,_,_,_,X,Y]
+```
 
 ### Inserting
 
+```bash
 // after -- [_,_,REF,NEW,_,_]
-    array.splice(array.indexOf(REF)+1, 0, NEW))
+list.splice(list.indexOf(REF)+1, 0, NEW))
+```
 
+```bash
 // before -- [_,_,NEW,REF,_,_]
-    array.splice(array.indexOf(REF), 0, NEW))
+list.splice(list.indexOf(REF), 0, NEW))
+```
 
 ### Replace items
 
-    array.splice(2, 1, X)    // array == [a,b,X,d,e]
+```bash
+list.splice(2, 1, X)    // list == [a,b,X,d,e]
+```
 
 ### Removing items
 
-    array.pop()              //=> e      array == [a,b,c,d]
-    array.shift()            //=> a      array == [b,c,d,e]
-    array.splice(2, 1)       //=> [c]    array == [a,b,d,e]
+```bash
+list.pop()              // → e    list == [a,b,c,d]
+list.shift()            // → a    list == [b,c,d,e]
+list.splice(2, 1)       // → [c]  list == [a,b,d,e]
+```
 
 ### Iterables
 
-    .filter(n => ...) => Array
+```bash
+.filter(n => ...) => array
+```
 
+```bash
 .find(n => ...)  // es6
 .findIndex(...)  // es6
+```
 
+```bash
 .every(n => ...) => Boolean // ie9+
 .some(n => ..) => Boolean   // ie9+
+```
 
+```bash
 .map(n => ...)   // ie9+
 .reduce((total, n) => total) // ie9+
 .reduceRight(...)
-
-
-
-
-
-
+```