JavaScript Exercise - 2

1. Write a JavaScript function to calculate the sum of values in an array.
   
   Test Data :
   console.log(sum([1,2,3]));
   console.log(sum([100,-200,3]));
   console.log(sum([1,2,'a',3]));
   Output :
   6
   -97
   6
   
   
   
2. Write a JavaScript function to convert degrees to radians
   
   
   
   Test Data :
   console.log(degrees_to_radians(45));
   0.7853981633974483
   
   
   
3. Write a JavaScript function to create random background color.
   
   random_bg_color();
   
   
4. Write a JavaScript function to print an integer with commas as thousands separators. 
   
   Test Data :
   console.log(thousands_separators(1000));
   "1,000"
   console.log(thousands_separators(10000.23));
   "10,000.23"
   console.log(thousands_separators(100000));
   "100,000"