feat:solving 01-strings-tasks.js

src/01-strings-tasks.js

@@ -18,8 +18,8 @@
  *   'aa',''    => 'aa'
  *   '',  'bb'  => 'bb'
  */
-function concatenateStrings(/* value1, value2 */) {
-  throw new Error('Not implemented');
+function concatenateStrings(value1, value2) {
+  return value1 + value2;
 }
 
 
@@ -34,8 +34,8 @@ function concatenateStrings(/* value1, value2 */) {
  *   'b'     => 1
  *   ''      => 0
  */
-function getStringLength(/* value */) {
-  throw new Error('Not implemented');
+function getStringLength(value) {
+  return value.length;
 }
 
 /**
@@ -51,8 +51,8 @@ function getStringLength(/* value */) {
  *   'John','Doe'      => 'Hello, John Doe!'
  *   'Chuck','Norris'  => 'Hello, Chuck Norris!'
  */
-function getStringFromTemplate(/* firstName, lastName */) {
-  throw new Error('Not implemented');
+function getStringFromTemplate(firstName, lastName) {
+  return `Hello, ${firstName} ${lastName}!`;
 }
 
 /**
@@ -65,8 +65,8 @@ function getStringFromTemplate(/* firstName, lastName */) {
  *   'Hello, John Doe!' => 'John Doe'
  *   'Hello, Chuck Norris!' => 'Chuck Norris'
  */
-function extractNameFromTemplate(/* value */) {
-  throw new Error('Not implemented');
+function extractNameFromTemplate(value) {
+  return value.split(',')[1].slice(0, -1).trim();
 }
 
 
@@ -80,9 +80,7 @@ function extractNameFromTemplate(/* value */) {
  *   'John Doe'  => 'J'
  *   'cat'       => 'c'
  */
-function getFirstChar(/* value */) {
-  throw new Error('Not implemented');
-}
+const getFirstChar = (value) => value.slice(0, 1);
 
 /**
  * Removes a leading and trailing whitespace characters from string.
@@ -95,8 +93,8 @@ function getFirstChar(/* value */) {
  *   'cat'              => 'cat'
  *   '\tHello, World! ' => 'Hello, World!'
  */
-function removeLeadingAndTrailingWhitespaces(/* value */) {
-  throw new Error('Not implemented');
+function removeLeadingAndTrailingWhitespaces(value) {
+  return value.trim(0, -1);
 }
 
 /**
@@ -110,10 +108,11 @@ function removeLeadingAndTrailingWhitespaces(/* value */) {
  *   'A', 5  => 'AAAAA'
  *   'cat', 3 => 'catcatcat'
  */
-function repeatString(/* value, count */) {
-  throw new Error('Not implemented');
+function repeatString(value, count) {
+  return value.repeat(count);
 }
 
+
 /**
  * Remove the first occurrence of string inside another string
  *
@@ -126,8 +125,8 @@ function repeatString(/* value, count */) {
  *   'I like legends', 'end' => 'I like legs',
  *   'ABABAB','BA' => 'ABAB'
  */
-function removeFirstOccurrences(/* str, value */) {
-  throw new Error('Not implemented');
+function removeFirstOccurrences(str, value) {
+  return str.replace(value, '');
 }
 
 /**
@@ -141,8 +140,8 @@ function removeFirstOccurrences(/* str, value */) {
  *   '<span>' => 'span'
  *   '<a>' => 'a'
  */
-function unbracketTag(/* str */) {
-  throw new Error('Not implemented');
+function unbracketTag(str) {
+  return str.slice(1, -1);
 }
 
 
@@ -156,8 +155,8 @@ function unbracketTag(/* str */) {
  *   'Thunderstruck' => 'THUNDERSTRUCK'
  *  'abcdefghijklmnopqrstuvwxyz' => 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
  */
-function convertToUpperCase(/* str */) {
-  throw new Error('Not implemented');
+function convertToUpperCase(str) {
+  return str.toUpperCase();
 }
 
 /**
@@ -175,8 +174,8 @@ function convertToUpperCase(/* str */) {
  *   ],
  *   '[email protected]' => ['[email protected]']
  */
-function extractEmails(/* str */) {
-  throw new Error('Not implemented');
+function extractEmails(str) {
+  return str.split(';');
 }
 
 /**
@@ -202,11 +201,13 @@ function extractEmails(/* str */) {
  *             '└──────────┘\n'
  *
  */
-function getRectangleString(/* width, height */) {
-  throw new Error('Not implemented');
+function getRectangleString(width, height) {
+  const first = `┌${'─'.repeat(width - 2)}┐\n`;
+  const middle = `│${' '.repeat(width - 2)}│\n`.repeat(height - 2);
+  const last = `└${'─'.repeat(width - 2)}┘\n`;
+  return first + middle + last;
 }
 
-
 /**
  * Encode specified string with ROT13 cipher
  * See details:  https://en.wikipedia.org/wiki/ROT13
@@ -223,10 +224,15 @@ function getRectangleString(/* width, height */) {
  *    => 'NOPQRSTUVWXYZABCDEFGHIJKLMnopqrstuvwxyzabcdefghijklm'
  *
  */
-function encodeToRot13(/* str */) {
-  throw new Error('Not implemented');
+function encodeToRot13(str) {
+  const GAP = 13;
+  const upper = 'ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLM';
+  const lower = 'abcdefghijklmnopqrstuvwxyzabcdefghijklm';
+  const charEncoded = (char) => GAP + char.charCodeAt() - (char.charCodeAt() < 97 ? 65 : 97);
+  return str.replace(/[a-zA-Z]/g, (s) => (s.charCodeAt() < 97 ? upper[charEncoded(s)] : lower[charEncoded(s)]));
 }
 
+
 /**
  * Returns true if the value is string; otherwise false.
  * @param {string} value
@@ -240,8 +246,8 @@ function encodeToRot13(/* str */) {
  *   isString('test') => true
  *   isString(new String('test')) => true
  */
-function isString(/* value */) {
-  throw new Error('Not implemented');
+function isString(value) {
+  return typeof value === 'string' || value instanceof String;
 }
 
 
@@ -269,8 +275,14 @@ function isString(/* value */) {
  *   'Q♠' => 50
  *   'K♠' => 51
  */
-function getCardId(/* value */) {
-  throw new Error('Not implemented');
+function getCardId(value) {
+  const deck = [
+    'A♣', '2♣', '3♣', '4♣', '5♣', '6♣', '7♣', '8♣', '9♣', '10♣', 'J♣', 'Q♣', 'K♣',
+    'A♦', '2♦', '3♦', '4♦', '5♦', '6♦', '7♦', '8♦', '9♦', '10♦', 'J♦', 'Q♦', 'K♦',
+    'A♥', '2♥', '3♥', '4♥', '5♥', '6♥', '7♥', '8♥', '9♥', '10♥', 'J♥', 'Q♥', 'K♥',
+    'A♠', '2♠', '3♠', '4♠', '5♠', '6♠', '7♠', '8♠', '9♠', '10♠', 'J♠', 'Q♠', 'K♠',
+  ];
+  return deck.indexOf(value);
 }
 
 

src/02-numbers-tasks.js

@@ -19,8 +19,8 @@
  *   5, 10 => 50
  *   5, 5  => 25
  */
-function getRectangleArea(/* width, height */) {
-  throw new Error('Not implemented');
+function getRectangleArea(width, height) {
+  return width * height;
 }
 
 
@@ -35,8 +35,8 @@ function getRectangleArea(/* width, height */) {
  *   3.14 => 19.729201864543903
  *   0    => 0
  */
-function getCircleCircumference(/* radius */) {
-  throw new Error('Not implemented');
+function getCircleCircumference(radius) {
+  return radius * 2 * Math.PI;
 }
 
 /**
@@ -51,8 +51,11 @@ function getCircleCircumference(/* radius */) {
  *  10, 0  => 5
  *  -3, 3  => 0
  */
-function getAverage(/* value1, value2 */) {
-  throw new Error('Not implemented');
+function getAverage(value1, value2) {
+  if (value1 === value2) return value1;
+  const vMax = Math.max(value1, value2);
+  const vMin = Math.min(value1, value2);
+  return vMin > 0 ? (vMax - vMin) / 2 : (vMax + vMin) / 2;
 }
 
 /**
@@ -70,8 +73,10 @@ function getAverage(/* value1, value2 */) {
  *   (0,0) (1,0)    => 1
  *   (-5,0) (10,-10) => 18.027756377319946
  */
-function getDistanceBetweenPoints(/* x1, y1, x2, y2 */) {
-  throw new Error('Not implemented');
+function getDistanceBetweenPoints(x1, y1, x2, y2) {
+  const a = x1 - x2;
+  const b = y1 - y2;
+  return Math.sqrt(a * a + b * b);
 }
 
 /**
@@ -86,8 +91,8 @@ function getDistanceBetweenPoints(/* x1, y1, x2, y2 */) {
  *   x + 8 = 0       => -8
  *   5*x = 0         => 0
  */
-function getLinearEquationRoot(/* a, b */) {
-  throw new Error('Not implemented');
+function getLinearEquationRoot(a, b) {
+  return -b / a;
 }
 
 
@@ -109,8 +114,9 @@ function getLinearEquationRoot(/* a, b */) {
  *   (0,1) (0,1)     => 0
  *   (0,1) (1,2)     => 0
  */
-function getAngleBetweenVectors(/* x1, y1, x2, y2 */) {
-  throw new Error('Not implemented');
+function getAngleBetweenVectors(x1, y1, x2, y2) {
+  return Math.acos((x1 * x2 + y1 * y2)
+  / (Math.sqrt(x1 ** 2 + y1 ** 2) * Math.sqrt(x2 ** 2 + y2 ** 2)));
 }
 
 /**
@@ -125,8 +131,8 @@ function getAngleBetweenVectors(/* x1, y1, x2, y2 */) {
  *     5     => 5
  *     0     => 0
  */
-function getLastDigit(/* value */) {
-  throw new Error('Not implemented');
+function getLastDigit(value) {
+  return Math.floor(value % 10);
 }
 
 
@@ -141,8 +147,8 @@ function getLastDigit(/* value */) {
  *     '37'     => 37
  * '-525.5'     => -525.5
  */
-function parseNumberFromString(/* value */) {
-  throw new Error('Not implemented');
+function parseNumberFromString(value) {
+  return +value;
 }
 
 /**
@@ -158,8 +164,8 @@ function parseNumberFromString(/* value */) {
  *   3,3,3   => 5.196152422706632
  *   1,2,3   => 3.741657386773941
  */
-function getParallelepipedDiagonal(/* a, b, c */) {
-  throw new Error('Not implemented');
+function getParallelepipedDiagonal(a, b, c) {
+  return Math.sqrt(a ** 2 + b ** 2 + c ** 2);
 }
 
 
@@ -180,8 +186,8 @@ function getParallelepipedDiagonal(/* a, b, c */) {
  *   1678, 2  => 1700
  *   1678, 3  => 2000
  */
-function roundToPowerOfTen(/* num, pow */) {
-  throw new Error('Not implemented');
+function roundToPowerOfTen(num, pow) {
+  return Math.round(num / 10 ** pow) * 10 ** pow;
 }
 
 /**
@@ -201,8 +207,12 @@ function roundToPowerOfTen(/* num, pow */) {
  *   16 => false
  *   17 => true
  */
-function isPrime(/* n */) {
-  throw new Error('Not implemented');
+function isPrime(n) {
+  if (n <= 1) return false;
+  for (let i = 2; i <= Math.sqrt(n); i += 1) {
+    if (n % i === 0) return false;
+  }
+  return true;
 }
 
 /**
@@ -220,8 +230,8 @@ function isPrime(/* n */) {
  *   toNumber(42, 0) => 42
  *   toNumber(new Number(42), 0) => 42
  */
-function toNumber(/* value, def */) {
-  throw new Error('Not implemented');
+function toNumber(value, def) {
+  return (typeof +value === 'number' && !Number.isNaN(+value)) ? +value : def;
 }
 
 module.exports = {