Moved level 1 file

01_Day_JavaScript_Refresher/level1.js

@@ -0,0 +1,95 @@
+const countries = [
+    'Albania',
+    'Bolivia',
+    'Canada',
+    'Denmark',
+    'Ethiopia',
+    'Finland',
+    'Germany',
+    'Hungary',
+    'Ireland',
+    'Japan',
+    'Kenya',
+  ]
+  
+  const webTechs = [
+    'HTML',
+    'CSS',
+    'JavaScript',
+    'React',
+    'Redux',
+    'Node',
+    'MongoDB',
+  ]
+//   1. Declare an empty array;
+const empty = []
+
+//  2.  Declare an array with more than 5 number of elements
+const moreThanFive = [1,2,3,4,5,6,7]
+
+//   3. Find the length of your array
+console.log(moreThanFive.length)
+
+//   4. Get the first item, the middle item and the last item of the array
+console.log(moreThanFive[0], moreThanFive[Math.floor(moreThanFive.length / 2)], moreThanFive[moreThanFive.length - 1])
+
+//   5. Declare an array called mixedDataTypes, put different data types in the array and find the length of the array. The array size should be greater than 5
+const mixedDataTypes = [1, 'two', false, () => 3, new Map(), new Set()]
+console.log(mixedDataTypes)
+
+//   6. Declare an array variable name itCompanies and assign initial values Facebook, Google, Microsoft, Apple, IBM, Oracle and Amazon
+const itCompanies = ['Facebook', 'Google', 'Microsoft', 'Apple', 'IBM', 'Oracle', 'Amazon']
+
+//   7. Print the array using console.log()
+console.log(itCompanies)
+
+//   8. Print the number of companies in the array
+console.log(itCompanies.length)
+
+//   9. Print the first company, middle and last company
+console.log(itCompanies[0], itCompanies[Math.floor(itCompanies.length / 2)], itCompanies[itCompanies.length - 1])
+
+//   10. Print out each company
+for(let i = 0; i < itCompanies.length; i++) console.log(itCompanies[i]);
+
+//   11. Change each company name to uppercase one by one and print them out
+for(let i = 0; i < itCompanies.length; i++) {
+    itCompanies[i] = itCompanies[i].toUpperCase()
+    console.log(itCompanies[i])
+};
+
+
+//   12. Print the array like as a sentence: Facebook, Google, Microsoft, Apple, IBM,Oracle and Amazon are big IT companies.
+
+
+//   13. Check if a certain company exists in the itCompanies array. If it exist return the company else return a company is not found
+
+
+//   14. Filter out companies which have more than one 'o' without the filter method
+
+
+//   15. Sort the array using sort() method
+
+
+//   16. Reverse the array using reverse() method
+
+
+//   17. Slice out the first 3 companies from the array
+
+
+//   18. Slice out the last 3 companies from the array
+
+
+//   19. Slice out the middle IT company or companies from the array
+
+
+//   20. Remove the first IT company from the array
+
+
+//   21. Remove the middle IT company or companies from the array
+
+
+//   22. Remove the last IT company from the array
+
+
+//   23. Remove all IT companies