Added samples

README.md

@@ -66,6 +66,7 @@ const anagrams = s => {
     return a;
   }, []);
 }
+// anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
 ```
 
 ### Average of array of numbers
@@ -75,6 +76,7 @@ Use `reduce()` to add each value to an accumulator, initialized with a value of
 ```js
 const average = arr =>
   arr.reduce( (acc , val) => acc + val, 0) / arr.length;
+// average([1,2,3]) -> 2
 ```
 
 ### Capitalize first letter of every word
@@ -83,6 +85,7 @@ Use `replace()` to match the first character of each word and `toUpperCase()` to
 
 ```js
 const capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
+// capitalizeEveryWord('hello world!') -> 'Hello World!'
 ```
 
 ### Capitalize first letter
@@ -93,6 +96,7 @@ Omit the `lowerRest` parameter to keep the rest of the string intact, or set it
 ```js
 const capitalize = (str, lowerRest = false) =>
   str.slice(0, 1).toUpperCase() + (lowerRest? str.slice(1).toLowerCase() : str.slice(1));
+// capitalize('myName', true) -> 'Myname'
 ```
 
 ### Check for palindrome
@@ -101,7 +105,8 @@ Convert string `toLowerCase()` and use `replace()` to remove non-alphanumeric ch
 Then, `split('')` into individual characters, `reverse()`, `join('')` and compare to the original, unreversed string, after converting it `tolowerCase()`.
 
 ```js
-const palindrome = str => (str.toLowerCase().replace(/[\W_]/g,'').split('').reverse().join('')==str.toLowerCase().replace(/[\W_]/g,''));
+const palindrome = str => (str.toLowerCase().replace(/[\W_]/g,'').split('').reverse().join('') === str.toLowerCase().replace(/[\W_]/g,''));
+// palindrome('taco cat') -> true
  ```
 
 ### Count occurrences of a value in array
@@ -110,6 +115,7 @@ Use `reduce()` to increment a counter each time you encounter the specific value
 
 ```js
 const countOccurrences = (arr, value) => arr.reduce((a, v) => v===value ? a + 1 : a + 0, 0);
+// countOccurrences([1,1,2,1,2,3], 1) -> 3
 ```
 
 ### Current URL
@@ -118,6 +124,7 @@ Use `window.location.href` to get current URL.
 
 ```js
 const currentUrl = _ => window.location.href;
+// currentUrl() -> 'https://google.com'
 ```
 
 ### Curry
@@ -129,7 +136,8 @@ Otherwise return a curried function `f` that expects the rest of the arguments.
 ```js
 const curry = f =>
   (...args) =>
-    args.length >= f.length ? f(...args) : (...otherArgs) => curry(f)(...args, ...otherArgs)
+    args.length >= f.length ? f(...args) : (...otherArgs) => curry(f)(...args, ...otherArgs);
+// curry(Math.pow)(2)(10) -> 1024
 ```
 
 ### Difference between arrays
@@ -138,6 +146,7 @@ Use `filter()` to remove values that are part of `values`, determined using `inc
 
 ```js
 const difference = (arr, values) => arr.filter(v => !values.includes(v));
+// difference([1,2,3], [1,2]) -> [3]
 ```
 
 ### Distance between two points
@@ -146,6 +155,7 @@ Use `Math.hypot()` to calculate the Euclidean distance between two points.
 
 ```js
 const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0, y1 - y0);
+// distance(1,1, 2,3) -> 2.23606797749979
 ```
 
 ### Divisible by number
@@ -154,6 +164,7 @@ Use the modulo operator (`%`) to check if the remainder is equal to `0`.
 
 ```js
 const isDivisible = (dividend, divisor) => dividend % divisor === 0;
+// isDivisible(6,3) -> true
 ```
 
 ### Escape regular expression
@@ -163,7 +174,7 @@ Use `replace()` to escape special characters.
 ```js
 const escapeRegExp = s =>
   s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
-}
+// escapeRegExp('(test)') -> \\(test\\)
 ```
 
 ### Even or odd number
@@ -173,6 +184,7 @@ Return `true` if the number is even, `false` if the number is odd.
 
 ```js
 const isEven = num => Math.abs(num) % 2 === 0;
+// isEven(3) -> false
 ```
 
 ### Factorial
@@ -182,7 +194,8 @@ If `n` is less than or equal to `1`, return `1`.
 Otherwise, return the product of `n` and the factorial of `n - 1`.
 
 ```js
-const factorial = n => n <= 1 ? 1 : n * factorial(n - 1)
+const factorial = n => n <= 1 ? 1 : n * factorial(n - 1);
+// factorial(6) -> 720
 ```
 
 ### Fibonacci array generator
@@ -197,6 +210,7 @@ const fibonacci = n =>
       acc.push( i>1 ? acc[i-1]+acc[i-2] : val);
       return acc;
     },[]);
+// fibonacci(5) -> [0,1,1,2,3]
 ```
 
 ### Filter out non-unique values in an array
@@ -216,6 +230,7 @@ Use `reduce()` to get all elements that are not arrays, flatten each element tha
 ```js
 const flatten = arr =>
   arr.reduce( (a, v) => a.concat( Array.isArray(v) ? flatten(v) : v ), []);
+// flatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
 ```
 
 ## Get scroll position
@@ -238,6 +253,7 @@ Otherwise, return the GCD of `y` and the remainder of the division `x/y`.
 
 ```js
 const gcd = (x , y) => !y ? x : gcd(y, x % y);
+// gcd (8, 36) -> 4
 ```
 
 ### Head of list
@@ -246,6 +262,7 @@ Return `arr[0]`.
 
 ```js
 const head = arr => arr[0];
+// head([1,2,3]) -> 1
 ```
 
 ### Initial of list
@@ -254,6 +271,7 @@ Return `arr.slice(0,-1)`.
 
 ```js
 const initial = arr => arr.slice(0,-1);
+// initial([1,2,3]) -> [1,2]
 ```
 
 ### Initialize array with range
@@ -264,6 +282,7 @@ You can omit `start` to use a default value of `0`.
 ```js
 const initializeArrayRange = (end, start = 0) =>
   Array.apply(null, Array(end-start)).map( (v,i) => i + start );
+// initializeArrayRange(5) -> [0,1,2,3,4]
 ```
 
 ### Initialize array with values
@@ -272,8 +291,8 @@ Use `Array(n)` to create an array of the desired length, `fill(v)` to fill it wi
 You can omit `v` to use a default value of `0`.
 
 ```js
-const initializeArray = (n, v = 0) =>
-  Array(n).fill(v);
+const initializeArray = (n, v = 0) => Array(n).fill(v);
+// initializeArray(5, 2) -> [2,2,2,2,2]
 ```
 
 ### Last of list
@@ -282,6 +301,7 @@ Return `arr.slice(-1)[0]`.
 
 ```js
 const last = arr => arr.slice(-1)[0];
+// last([1,2,3]) -> 3
 ```
 
 ### Measure time taken by function
@@ -295,6 +315,7 @@ const timeTaken = (f,...args) => {
   console.log(performance.now() - t0);
   return r;
 }
+// timeTaken(Math.pow, 2, 10) -> 1024 (0.010000000009313226 logged in console)
 ```
 
 ### Object from key-value pairs
@@ -302,7 +323,8 @@ const timeTaken = (f,...args) => {
 Use `Array.reduce()` to create and combine key-value pairs.
 
 ```js
-const objectFromPairs = arr => arr => arr.reduce((a,b) => (a[b[0]] = b[1], a), {});
+const objectFromPairs = arr => arr.reduce((a,b) => (a[b[0]] = b[1], a), {});
+// objectFromPairs([['a',1],['b',2]]) -> {a: 1, b: 2}
 ```
 
 ### Powerset
@@ -312,6 +334,7 @@ Use `reduce()` combined with `map()` to iterate over elements and combine into a
 ```js
 const powerset = arr =>
   arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
+// powerset([1,2]) -> [[], [1], [2], [2,1]]
 ```
 
 ### Random number in range
@@ -320,6 +343,7 @@ Use `Math.random()` to generate a random value, map it to the desired range usin
 
 ```js
 const randomInRange = (min, max) => Math.random() * (max - min) + min;
+// randomInRange(2,10) -> 6.0211363285087005
 ```
 
 ### Randomize order of array
@@ -327,7 +351,8 @@ const randomInRange = (min, max) => Math.random() * (max - min) + min;
 Use `sort()` to reorder elements, utilizing `Math.random()` to randomize the sorting.
 
 ```js
-const randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1)
+const randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1);
+// randomizeOrder([1,2,3]) -> [1,3,2]
 ```
 
 ### Redirect to URL
@@ -338,6 +363,7 @@ Pass a second argument to simulate a link click (`true` - default) or an HTTP re
 ```js
 const redirect = (url, asLink = true) =>
   asLink ? window.location.href = url : window.location.replace(url);
+// redirect('https://google.com')
 ```
 
 ### Reverse a string
@@ -347,6 +373,7 @@ Combine characters to get a string using `join('')`.
 
 ```js
 const reverseString = str => [...str].reverse().join('');
+// reverseString('foobar') -> 'raboof'
 ```
 
 ### RGB to hexadecimal
@@ -357,6 +384,7 @@ Combine values using `join('')`.
 ```js
 const rgbToHex = (r, g, b) =>
   [r,g,b].map( v => v.toString(16).padStart(2,'0')).join('');
+// rgbToHex(0, 127, 255) -> '007fff'
 ```
 
 ### Scroll to top
@@ -372,6 +400,7 @@ const scrollToTop = _ => {
     window.scrollTo(0, c - c/8);
   }
 }
+// scrollToTop()
 ```
 
 ### Similarity between arrays
@@ -379,7 +408,8 @@ const scrollToTop = _ => {
 Use `filter()` to remove values that are not part of `values`, determined using `includes()`.
 
 ```js
-const difference = (arr, values) => arr.filter(v => values.includes(v));
+const similarity = (arr, values) => arr.filter(v => values.includes(v));
+// similarity([1,2,3], [1,2,4]) -> [1,2]
 ```
 
 ### Sort characters in string (alphabetical)
@@ -389,6 +419,7 @@ Split the string using `split('')`, `sort()` utilizing `localeCompare()`, recomb
 ```js
 const sortCharactersInString = str =>
   str.split('').sort( (a,b) => a.localeCompare(b) ).join('');
+// sortCharactersInString('cabbage') -> 'aabbceg'
 ```
 
 ### Sum of array of numbers
@@ -398,6 +429,7 @@ Use `reduce()` to add each value to an accumulator, initialized with a value of
 ```js
 const sum = arr =>
   arr.reduce( (acc , val) => acc + val, 0);
+// sum([1,2,3,4]) -> 10
 ```
 
 ### Swap values of two variables
@@ -406,6 +438,7 @@ Use array destructuring to swap values between two variables.
 
 ```js
 [varA, varB] = [varB, varA];
+// [x, y] = [y, x]
 ```
 
 ### Tail of list
@@ -414,6 +447,7 @@ Return `arr.slice(1)`.
 
 ```js
 const tail = arr => arr.slice(1);
+// tail([1,2,3]) -> [2,3]
 ```
 
 ### Unique values of array
@@ -434,6 +468,7 @@ Pass `location.search` as the argument to apply to the current `url`.
 ```js
 const getUrlParameters = url =>
   Object.assign(...url.match(/([^?=&]+)(=([^&]*))?/g).map(m => {[f,v] = m.split('='); return {[f]:v}}));
+// getUrlParameters('http://url.com/page?name=Adam&surname=Smith') -> {name: 'Adam', surname: 'Smith'}
 ```
 
 ### UUID generator
@@ -444,7 +479,8 @@ Use `crypto` API to generate a UUID, compliant with [RFC4122](https://www.ietf.o
 const uuid = _ =>
   ( [1e7]+-1e3+-4e3+-8e3+-1e11 ).replace( /[018]/g, c =>
     (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
-  )
+  );
+// uuid() -> '7982fcfe-5721-4632-bede-6000885be57d'
 ```
 
 ### Validate number
@@ -454,6 +490,7 @@ Use `isFinite()` to check if the number is finite.
 
 ```js
 const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n);
+// validateNumber('10') -> true
 ```
 
 ## Credits

snippets/Check_for_palindrome.md

@@ -4,5 +4,6 @@ Convert string `toLowerCase()` and use `replace()` to remove non-alphanumeric ch
 Then, `split('')` into individual characters, `reverse()`, `join('')` and compare to the original, unreversed string, after converting it `tolowerCase()`.
 
 ```js
-const palindrome = str => (str.toLowerCase().replace(/[\W_]/g,'').split('').reverse().join('')==str.toLowerCase().replace(/[\W_]/g,''));
+const palindrome = str => (str.toLowerCase().replace(/[\W_]/g,'').split('').reverse().join('') === str.toLowerCase().replace(/[\W_]/g,''));
+// palindrome('taco cat') -> true
  ```

snippets/RGB-to-hexadecimal.md

@@ -6,4 +6,5 @@ Combine values using `join('')`.
 ```js
 const rgbToHex = (r, g, b) =>
   [r,g,b].map( v => v.toString(16).padStart(2,'0')).join('');
+// rgbToHex(0, 127, 255) -> '007fff'
 ```

snippets/URL-parameters.md

@@ -7,4 +7,5 @@ Pass `location.search` as the argument to apply to the current `url`.
 ```js
 const getUrlParameters = url =>
   Object.assign(...url.match(/([^?=&]+)(=([^&]*))?/g).map(m => {[f,v] = m.split('='); return {[f]:v}}));
+// getUrlParameters('http://url.com/page?name=Adam&surname=Smith') -> {name: 'Adam', surname: 'Smith'}
 ```

snippets/UUID-generator.md

@@ -6,5 +6,6 @@ Use `crypto` API to generate a UUID, compliant with [RFC4122](https://www.ietf.o
 const uuid = _ =>
   ( [1e7]+-1e3+-4e3+-8e3+-1e11 ).replace( /[018]/g, c =>
     (c ^ crypto.getRandomValues(new Uint8Array(1))[0] & 15 >> c / 4).toString(16)
-  )
+  );
+// uuid() -> '7982fcfe-5721-4632-bede-6000885be57d'
 ```

snippets/anagrams-of-string-(with-duplicates).md

@@ -13,4 +13,5 @@ const anagrams = s => {
     return a;
   }, []);
 }
+// anagrams('abc') -> ['abc','acb','bac','bca','cab','cba']
 ```

snippets/average-of-array-of-numbers.md

@@ -5,4 +5,5 @@ Use `reduce()` to add each value to an accumulator, initialized with a value of
 ```js
 const average = arr =>
   arr.reduce( (acc , val) => acc + val, 0) / arr.length;
+// average([1,2,3]) -> 2
 ```

snippets/capitalize-first-letter-of-every-word.md

@@ -4,4 +4,5 @@ Use `replace()` to match the first character of each word and `toUpperCase()` to
 
 ```js
 const capitalizeEveryWord = str => str.replace(/\b[a-z]/g, char => char.toUpperCase());
+// capitalizeEveryWord('hello world!') -> 'Hello World!'
 ```

snippets/capitalize-first-letter.md

@@ -6,4 +6,5 @@ Omit the `lowerRest` parameter to keep the rest of the string intact, or set it
 ```js
 const capitalize = (str, lowerRest = false) =>
   str.slice(0, 1).toUpperCase() + (lowerRest? str.slice(1).toLowerCase() : str.slice(1));
+// capitalize('myName', true) -> 'Myname'
 ```

snippets/count-occurrences-of-a-value-in-array.md

@@ -4,4 +4,5 @@ Use `reduce()` to increment a counter each time you encounter the specific value
 
 ```js
 const countOccurrences = (arr, value) => arr.reduce((a, v) => v===value ? a + 1 : a + 0, 0);
+// countOccurrences([1,1,2,1,2,3], 1) -> 3
 ```

snippets/current-URL.md

@@ -4,4 +4,5 @@ Use `window.location.href` to get current URL.
 
 ```js
 const currentUrl = _ => window.location.href;
+// currentUrl() -> 'https://google.com'
 ```

snippets/curry.md

@@ -7,5 +7,6 @@ Otherwise return a curried function `f` that expects the rest of the arguments.
 ```js
 const curry = f =>
   (...args) =>
-    args.length >= f.length ? f(...args) : (...otherArgs) => curry(f)(...args, ...otherArgs)
+    args.length >= f.length ? f(...args) : (...otherArgs) => curry(f)(...args, ...otherArgs);
+// curry(Math.pow)(2)(10) -> 1024
 ```

snippets/difference-between-arrays.md

@@ -4,4 +4,5 @@ Use `filter()` to remove values that are part of `values`, determined using `inc
 
 ```js
 const difference = (arr, values) => arr.filter(v => !values.includes(v));
+// difference([1,2,3], [1,2]) -> [3]
 ```

snippets/distance-between-two-points.md

@@ -4,4 +4,5 @@ Use `Math.hypot()` to calculate the Euclidean distance between two points.
 
 ```js
 const distance = (x0, y0, x1, y1) => Math.hypot(x1 - x0, y1 - y0);
+// distance(1,1, 2,3) -> 2.23606797749979
 ```

snippets/divisible-by-number.md

@@ -4,4 +4,5 @@ Use the modulo operator (`%`) to check if the remainder is equal to `0`.
 
 ```js
 const isDivisible = (dividend, divisor) => dividend % divisor === 0;
+// isDivisible(6,3) -> true
 ```

snippets/escape-regular-expression.md

@@ -5,5 +5,5 @@ Use `replace()` to escape special characters.
 ```js
 const escapeRegExp = s =>
   s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
-}
+// escapeRegExp('(test)') -> \\(test\\)
 ```

snippets/even-or-odd-number.md

@@ -5,4 +5,5 @@ Return `true` if the number is even, `false` if the number is odd.
 
 ```js
 const isEven = num => Math.abs(num) % 2 === 0;
+// isEven(3) -> false
 ```

snippets/factorial.md

@@ -5,5 +5,6 @@ If `n` is less than or equal to `1`, return `1`.
 Otherwise, return the product of `n` and the factorial of `n - 1`.
 
 ```js
-const factorial = n => n <= 1 ? 1 : n * factorial(n - 1)
+const factorial = n => n <= 1 ? 1 : n * factorial(n - 1);
+// factorial(6) -> 720
 ```

snippets/fibonacci-array-generator.md

@@ -10,4 +10,5 @@ const fibonacci = n =>
       acc.push( i>1 ? acc[i-1]+acc[i-2] : val);
       return acc;
     },[]);
+// fibonacci(5) -> [0,1,1,2,3]
 ```

snippets/flatten-array.md

@@ -6,4 +6,5 @@ Use `reduce()` to get all elements that are not arrays, flatten each element tha
 ```js
 const flatten = arr =>
   arr.reduce( (a, v) => a.concat( Array.isArray(v) ? flatten(v) : v ), []);
+// flatten([1,[2],[[3],4],5]) -> [1,2,3,4,5]
 ```

snippets/greatest-common-divisor-(GCD).md

@@ -6,4 +6,5 @@ Otherwise, return the GCD of `y` and the remainder of the division `x/y`.
 
 ```js
 const gcd = (x , y) => !y ? x : gcd(y, x % y);
+// gcd (8, 36) -> 4
 ```

snippets/head-of-list.md

@@ -4,4 +4,5 @@ Return `arr[0]`.
 
 ```js
 const head = arr => arr[0];
+// head([1,2,3]) -> 1
 ```

snippets/initial-of-list.md

@@ -4,4 +4,5 @@ Return `arr.slice(0,-1)`.
 
 ```js
 const initial = arr => arr.slice(0,-1);
+// initial([1,2,3]) -> [1,2]
 ```

snippets/initialize-array-with-range.md

@@ -6,4 +6,5 @@ You can omit `start` to use a default value of `0`.
 ```js
 const initializeArrayRange = (end, start = 0) =>
   Array.apply(null, Array(end-start)).map( (v,i) => i + start );
+// initializeArrayRange(5) -> [0,1,2,3,4]
 ```

snippets/initialize-array-with-values.md

@@ -4,6 +4,6 @@ Use `Array(n)` to create an array of the desired length, `fill(v)` to fill it wi
 You can omit `v` to use a default value of `0`.
 
 ```js
-const initializeArray = (n, v = 0) =>
-  Array(n).fill(v);
+const initializeArray = (n, v = 0) => Array(n).fill(v);
+// initializeArray(5, 2) -> [2,2,2,2,2]
 ```

snippets/last-of-list.md

@@ -4,4 +4,5 @@ Return `arr.slice(-1)[0]`.
 
 ```js
 const last = arr => arr.slice(-1)[0];
+// last([1,2,3]) -> 3
 ```

snippets/measure-time-taken-by-function.md

@@ -9,4 +9,5 @@ const timeTaken = (f,...args) => {
   console.log(performance.now() - t0);
   return r;
 }
+// timeTaken(Math.pow, 2, 10) -> 1024 (0.010000000009313226 logged in console)
 ```

snippets/object-from-key-value-pairs.md

@@ -3,5 +3,6 @@
 Use `Array.reduce()` to create and combine key-value pairs.
 
 ```js
-const objectFromPairs = arr => arr => arr.reduce((a,b) => (a[b[0]] = b[1], a), {});
+const objectFromPairs = arr => arr.reduce((a,b) => (a[b[0]] = b[1], a), {});
+// objectFromPairs([['a',1],['b',2]]) -> {a: 1, b: 2}
 ```

snippets/powerset.md

@@ -5,4 +5,5 @@ Use `reduce()` combined with `map()` to iterate over elements and combine into a
 ```js
 const powerset = arr =>
   arr.reduce( (a,v) => a.concat(a.map( r => [v].concat(r) )), [[]]);
+// powerset([1,2]) -> [[], [1], [2], [2,1]]
 ```

snippets/random-number-in-range.md

@@ -4,4 +4,5 @@ Use `Math.random()` to generate a random value, map it to the desired range usin
 
 ```js
 const randomInRange = (min, max) => Math.random() * (max - min) + min;
+// randomInRange(2,10) -> 6.0211363285087005
 ```

snippets/randomize-order-of-array.md

@@ -3,5 +3,6 @@
 Use `sort()` to reorder elements, utilizing `Math.random()` to randomize the sorting.
 
 ```js
-const randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1)
+const randomizeOrder = arr => arr.sort( (a,b) => Math.random() >= 0.5 ? -1 : 1);
+// randomizeOrder([1,2,3]) -> [1,3,2]
 ```

snippets/redirect-to-url.md

@@ -6,4 +6,5 @@ Pass a second argument to simulate a link click (`true` - default) or an HTTP re
 ```js
 const redirect = (url, asLink = true) =>
   asLink ? window.location.href = url : window.location.replace(url);
+// redirect('https://google.com')
 ```

snippets/reverse-a-string.md

@@ -5,4 +5,5 @@ Combine characters to get a string using `join('')`.
 
 ```js
 const reverseString = str => [...str].reverse().join('');
+// reverseString('foobar') -> 'raboof'
 ```

snippets/scroll-to-top.md

@@ -11,4 +11,5 @@ const scrollToTop = _ => {
     window.scrollTo(0, c - c/8);
   }
 }
+// scrollToTop()
 ```

snippets/similarity-between-arrays.md

@@ -3,5 +3,6 @@
 Use `filter()` to remove values that are not part of `values`, determined using `includes()`.
 
 ```js
-const difference = (arr, values) => arr.filter(v => values.includes(v));
+const similarity = (arr, values) => arr.filter(v => values.includes(v));
+// similarity([1,2,3], [1,2,4]) -> [1,2]
 ```

snippets/sort-characters-in-string-(alphabetical).md

@@ -5,4 +5,5 @@ Split the string using `split('')`, `sort()` utilizing `localeCompare()`, recomb
 ```js
 const sortCharactersInString = str =>
   str.split('').sort( (a,b) => a.localeCompare(b) ).join('');
+// sortCharactersInString('cabbage') -> 'aabbceg'
 ```

snippets/sum-of-array-of-numbers.md

@@ -5,4 +5,5 @@ Use `reduce()` to add each value to an accumulator, initialized with a value of
 ```js
 const sum = arr =>
   arr.reduce( (acc , val) => acc + val, 0);
+// sum([1,2,3,4]) -> 10
 ```

snippets/swap-values-of-two-variables.md

@@ -4,4 +4,5 @@ Use array destructuring to swap values between two variables.
 
 ```js
 [varA, varB] = [varB, varA];
+// [x, y] = [y, x]
 ```

snippets/tail-of-list.md

@@ -4,4 +4,5 @@ Return `arr.slice(1)`.
 
 ```js
 const tail = arr => arr.slice(1);
+// tail([1,2,3]) -> [2,3]
 ```

snippets/validate-number.md

@@ -5,4 +5,5 @@ Use `isFinite()` to check if the number is finite.
 
 ```js
 const validateNumber = n => !isNaN(parseFloat(n)) && isFinite(n);
+// validateNumber('10') -> true
 ```