done

src/array.js

@@ -10,9 +10,15 @@
  *    ['Array', 'Number', 'string'], 'Date'    => -1
  *    [0, 1, 2, 3, 4, 5], 5    => 5
  */
+
 function findElement(arr, value) {
-	throw new Error("Not implemented");
-}
+	for (let i = 0; i < arr.length; i++) {
+	  if (arr[i] === value) {
+		return i;
+	  }
+	}
+	return -1;
+  }
 
 /**
  * Returns the doubled array - elements of the specified array are repeated twice
@@ -26,9 +32,10 @@ function findElement(arr, value) {
  *    [0, 1, 2, 3, 4, 5] => [0, 1, 2, 3, 4, 5,   0, 1, 2, 3, 4, 5]
  *    [] => []
  */
+
 function doubleArray(arr) {
-	throw new Error("Not implemented");
-}
+	return arr.concat(arr);
+  }
 
 /**
  * Returns an array of positive numbers from the specified array in original order
@@ -41,9 +48,10 @@ function doubleArray(arr) {
  *    [-1, 2, -5, -4, 0] => [ 2 ]
  *    [] => []
  */
+
 function getArrayOfPositives(arr) {
-	throw new Error("Not implemented");
-}
+	return arr.filter(num => num > 0);
+  }
 
 /**
  * Removes falsy values from the specified array
@@ -58,9 +66,10 @@ function getArrayOfPositives(arr) {
  *    [ 1, 2, 3, 4, 5, 'false' ]         => [ 1, 2, 3, 4, 5, 'false' ]
  *    [ false, 0, NaN, '', undefined ]   => [ ]
  */
+
 function removeFalsyValues(arr) {
-	throw new Error("Not implemented");
-}
+	return arr.filter(item => !!item);
+  }
 
 /**
  * Returns the array of string lengths from the specified string array.
@@ -72,9 +81,10 @@ function removeFalsyValues(arr) {
  *    [ '', 'a', 'bc', 'def', 'ghij' ]  => [ 0, 1, 2, 3, 4 ]
  *    [ 'angular', 'react', 'ember' ] => [ 7, 5, 5 ]
  */
+
 function getStringsLength(arr) {
-	throw new Error("Not implemented");
-}
+	return arr.map(str => str.length);
+  }
 
 /**
  * Returns the sum of all items in the specified array of numbers
@@ -88,9 +98,10 @@ function getStringsLength(arr) {
  *   [ -1, 1, -1, 1 ]      => 0
  *   [ 1, 10, 100, 1000 ]  => 1111
  */
+
 function getItemsSum(arr) {
-	throw new Error("Not implemented");
-}
+	return arr.reduce((sum, num) => sum + num, 0);
+  }
 
 module.exports = {
 	findElement,

src/bulb.js

@@ -5,16 +5,30 @@ const BULB_OFF_URL = "https://i.postimg.cc/KjK1wL3c/bulb-off.png";
 TODO:
 Fetch the status of the 'flexSwitchCheckChecked' checkbox and call the appropiate function to turn the bulb on or off
 */
-function lightSwitch() {}
+
+function lightSwitch() {
+    const checkbox = document.getElementById('flexSwitchCheckChecked');
+    const bulbImage = document.getElementById('bulb');
+
+    if (checkbox.checked) {
+      bulb_on(bulbImage);
+    } else {
+      bulb_off(bulbImage);
+    }
+  }
 
 /*
 TODO:
 Set the "bulb" element's Image src to be the image specified by BULB_ON_URL
 */
-function bulb_on() {}
+function bulb_on(bulbImage) {
+    bulbImage.src = BULB_ON_URL;
+  }
 
 /*
 TODO:
 Set the "bulb" element's Image src to be the image specified by BULB_OFF_URL
 */
-function bulb_off() {}
+function bulb_off(bulbImage) {
+    bulbImage.src = BULB_OFF_URL;
+  }

src/conditionalAndLoops.js

@@ -18,9 +18,18 @@
  *  21 => 'Fizz'
  *
  */
+
 function getFizzBuzz(num) {
-	throw new Error("Not implemented");
-}
+	if (num % 3 === 0 && num % 5 === 0) {
+	  return 'FizzBuzz';
+	} else if (num % 3 === 0) {
+	  return 'Fizz';
+	} else if (num % 5 === 0) {
+	  return 'Buzz';
+	} else {
+	  return num;
+	}
+  }
 
 /**
  * Returns the factorial of the specified integer n.
@@ -33,9 +42,14 @@ function getFizzBuzz(num) {
  *   5  => 120
  *   10 => 3628800
  */
+
 function getFactorial(n) {
-	throw new Error("Not implemented");
-}
+	if (n === 0 || n === 1) {
+	  return 1;
+	} else {
+	  return n * factorial(n - 1);
+	}
+  }
 
 /**
  * Returns the sum of integer numbers between n1 and n2 (inclusive).
@@ -49,9 +63,16 @@ function getFactorial(n) {
  *   5,10  =>  45 ( = 5+6+7+8+9+10 )
  *   -1,1  =>  0  ( = -1 + 0 + 1 )
  */
+
 function getSumBetweenNumbers(n1, n2) {
-	throw new Error("Not implemented");
-}
+	let sum = 0;
+
+	for (let i = n1; i <= n2; i++) {
+	  sum += i;
+	}
+
+	return sum;
+  }
 
 /**
  * Returns true, if a triangle can be built with the specified sides a,b,c and false
@@ -68,9 +89,10 @@ function getSumBetweenNumbers(n1, n2) {
  *   10,1,1   =>  false
  *   10,10,10 =>  true
  */
+
 function isTriangle(a, b, c) {
-	throw new Error("Not implemented");
-}
+	return a + b > c && a + c > b && b + c > a;
+  }
 
 /**
  * Reverse the specified string (put all chars in reverse order)
@@ -84,9 +106,10 @@ function isTriangle(a, b, c) {
  * 'rotator' => 'rotator'
  * 'noon' => 'noon'
  */
+
 function reverseString(str) {
-	throw new Error("Not implemented");
-}
+	return str.split('').reverse().join('');
+  }
 
 /**
  * Returns true if the specified string has the balanced brackets and false otherwise.
@@ -109,9 +132,30 @@ function reverseString(str) {
  *   '{)' = false
  *   '{[(<{[]}>)]}' = true
  */
+
 function isBracketsBalanced(str) {
-	throw new Error("Not implemented");
-}
+	const stack = [];
+	const openingBrackets = '([{<';
+	const closingBrackets = ')]}>';
+	const bracketPairs = {
+	  ')': '(',
+	  ']': '[',
+	  '}': '{',
+	  '>': '<',
+	};
+
+	for (const char of str) {
+	  if (openingBrackets.includes(char)) {
+		stack.push(char);
+	  } else if (closingBrackets.includes(char)) {
+		if (stack.length === 0 || stack.pop() !== bracketPairs[char]) {
+		  return false;
+		}
+	  }
+	}
+
+	return stack.length === 0;
+  }
 
 /**
  * Returns the human readable string of time period specified by the start and end time.
@@ -144,9 +188,43 @@ function isBracketsBalanced(str) {
  *   Date('2000-01-01 01:00:00.100'), Date('2015-01-02 03:00:05.000')  => '15 years ago'
  *
  */
+
 function timespanToHumanString(startDate, endDate) {
-	throw new Error("Not implemented");
-}
+	const diffInMillis = endDate - startDate;
+	const diffInSeconds = Math.floor(diffInMillis / 1000);
+	const diffInMinutes = Math.floor(diffInSeconds / 60);
+	const diffInHours = Math.floor(diffInMinutes / 60);
+	const diffInDays = Math.floor(diffInHours / 24);
+	const diffInMonths = Math.floor(diffInDays / 30);
+	const diffInYears = Math.floor(diffInDays / 365);
+
+	if (diffInSeconds <= 45) {
+	  return 'a few seconds ago';
+	} else if (diffInSeconds <= 90) {
+	  return 'a minute ago';
+	} else if (diffInMinutes <= 45) {
+	  return `${diffInMinutes} minutes ago`;
+	} else if (diffInMinutes <= 90) {
+	  return 'an hour ago';
+	} else if (diffInHours <= 22) {
+	  return `${diffInHours} hours ago`;
+	} else if (diffInHours <= 36) {
+	  return 'a day ago';
+	} else if (diffInDays <= 25) {
+	  return `${diffInDays} days ago`;
+	} else if (diffInDays <= 45) {
+	  return 'a month ago';
+	} else if (diffInDays <= 345) {
+	  return `${diffInMonths} months ago`;
+	} else if (diffInDays <= 545) {
+	  return 'a year ago';
+	} else {
+	  return `${diffInYears} years ago`;
+	}
+  }
+
+
+
 
 /**
  * Returns the string with n-ary (binary, ternary, etc, where n<=10) representation of
@@ -168,9 +246,10 @@ function timespanToHumanString(startDate, endDate) {
  *    365, 4  => '11231'
  *    365, 10 => '365'
  */
+
 function toNaryString(num, n) {
-	throw new Error("Not implemented");
-}
+	return num.toString(n);
+  }
 
 module.exports = {
 	getFizzBuzz,

src/numbers.js

@@ -9,9 +9,10 @@
  *   5, 10 => 50
  *   5, 5  => 25
  */
+
 function getRectangleArea(width, height) {
-	throw new Error("Not implemented");
-}
+	return width * height;
+  }
 
 /**
  * Returns an average of two given numbers.
@@ -26,8 +27,10 @@ function getRectangleArea(width, height) {
  *  -3, 3  => 0
  */
 function getAverage(value1, value2) {
-	throw new Error("Not implemented");
-}
+	return (value1 + value2) / 2;
+  }
+
+//   console.log(getAverage(6, 5))
 
 /**
  * Returns a root of linear equation a*x + b = 0 given by coefficients a and b.
@@ -42,8 +45,8 @@ function getAverage(value1, value2) {
  *   5*x = 0         => 0
  */
 function getLinearEquationRoot(a, b) {
-	throw new Error("Not implemented");
-}
+	return -b / a;
+  }
 
 /**
  * Returns a last digit of a integer number.
@@ -58,8 +61,8 @@ function getLinearEquationRoot(a, b) {
  *     0     => 0
  */
 function getLastDigit(value) {
-	throw new Error("Not implemented");
-}
+	return value % 10;
+  }
 
 /**
  * Returns a number by given string representation.
@@ -73,8 +76,8 @@ function getLastDigit(value) {
  * '-525.5'     => -525.5
  */
 function parseNumberFromString(value) {
-	throw new Error("Not implemented");
-}
+	return parseFloat(value);
+  }
 
 /**
  * Returns true is the number is prime; otherwise false.
@@ -94,8 +97,26 @@ function parseNumberFromString(value) {
  *   17 => true
  */
 function isPrime(n) {
-	throw new Error("Not implemented");
-}
+	if (n <= 1) {
+	  return false;
+	}
+
+	if (n <= 3) {
+	  return true;
+	}
+
+	if (n % 2 === 0 || n % 3 === 0) {
+	  return false;
+	}
+
+	for (let i = 5; i * i <= n; i += 6) {
+	  if (n % i === 0 || n % (i + 2) === 0) {
+		return false;
+	  }
+	}
+
+	return true;
+  }
 
 module.exports = {
 	getRectangleArea,