week2practice

//*************************PROBLEM 1*************************
// plan:
//set counter 0
//get key value from obj
//check if KEY includes cute or adorable, then counter++
//check if VALUE includes cute or adorable, then counter++
//return counter

const miahsCats = (obj)=>{
  let counter = 0;
  for([key,value] of Object.entries(obj)){
      let current_key = key.toLowerCase();
      let current_value = value.toLowerCase();

      if(current_key.includes('cute') ||  current_key.includes('adorable')){
          counter ++;
      }
      if(current_value.includes('cute') ||  current_value.includes('adorable')){
          counter ++;
      }
  }
  return counter;
}


//*************************PROBLEM 2*************************
// plan: do 2 splits and check w/ includes
// split_by_comma
// iterate split_by_comma & split each ele by semi-colon

const spiderManWriters = (string) =>{
  // split_by_comma = ['Angela T: wrote about Spiderman', 'Miah B: no Spiderman']
  const split_by_comma = string.split(', ');

  // split_by_semi = [['Angela T', 'wrote about Spiderman'], ...]
  const split_by_semi = split_by_comma.map((kv_string)=>kv_string.split(': '))

  // compare w/ includes for each author and add to obj.
  const who_didnt_write_about_spidy = {};

  split_by_semi.forEach(ele=>{ //ele = ['Angela T', 'wrote about Spiderman']
      if(ele[1] !== undefined && ele[1].includes('no Spiderman')){
          // console.log(ele[0], ele[1])
          who_didnt_write_about_spidy[ele[0]] = ele[1];
      }
  })
  return who_didnt_write_about_spidy;
}



//*************************PROBLEM 3*************************
// plan:
// get percentage to pay after discount
// iterate through wishlist
// for each obj, we get discounted price (percent to pay * price)
// add discounted price to counter

const applyCoupon = (discount, wishList) =>{
  const percent_to_pay = (100 - discount) / 100; // (100 - 10) / 100 = 0.9
  let total_price_after_discount = 0;

  wishList.forEach(ele => { //ele = {name: "Xbox", price: 80},
      const ele_price = ele["price"]
      const discounted_price = percent_to_pay * ele_price; // 72 = 0.9 * 80

      total_price_after_discount += discounted_price;
  })
  // console.log(total_price_after_discount);
  return total_price_after_discount;
}



//*************************PROBLEM 4*************************
// plan:
// declare total
// outer func returns declare inner function
// inner func sets total to dice * roll (closure = access to an outer func’s scope from inner)
// inner func returns total

//using arrow function expression
const dynamicDice = dice =>{
let total;
return roll => {
  total = dice * roll;
  return total;
}
}

//using vanilla function declaration
function dynamicDice2(dice){
let total;
return function(roll){ //inner function creates a CLOSURE over 'total' variable
  total = dice * roll;
  return total;
}
}




//*************************PROBLEM 5*************************
//note: *given at least one arg

//plan:
//function parameter takes in arguments w/ rest (...nums) --> nums is now an array of numbers
//iterate through 'nums' and sum up total

// ------------------vanilla for loop-------------------
// const manyArgs = (...args) => {
//     let total = args[0];

//     for(let i=1; i<args.length; i++){
//         total *= args[i];
//     }
//     return total;
// }

// ------------------with map-------------------
// const manyArgs = (...args) => {
//     let total = 1;

//     //here we only use array map method as an iterator and multiplying num to total
//     //NOTE: This is INEFFICIENT for memory as we do not need the array provided by map
//     const unused_array_from_map = args.map(num => total*=num) //arrow func with IMPLICIT return logic
//     // console.log(unused_array_from_map) //see what this prints
//     return total;
// }

// manyArgs(1, 2, 3, 4, 5, 6, 7) // 5040
// manyArgs(1, 2, 5, 6, 7) // 420


// ------------------with forEach-------------------
// const manyArgs = (...args) => {
//     let total = 1;

//     //forEach does not return an array, just iterates and allow us access of ele in args.
//     args.forEach( (ele) => total*=ele)
//     return total;
// }


// ------------------with reduce-------------------
const manyArgs = (...args) => {

  // DECLARATION of callback to be passed to reduce. total = accum
  const multiply_accum_callback = (total, num) =>{
      let new_total = total*num
      return new_total //explicit return of the new 'accum' value to be used by reduce.
  }

  const default_total_value = 1;
  // here, reduce takes in a callback function and a default value.
  // callback returns: new accum value after applying logic that will be tracked
  let final_total = args.reduce(multiply_accum_callback, default_total_value)
  //if no default provided, reduce will make default accum the first ele in the array (args).

  return final_total;
}