Chapter 3 Exercises

Javascript Programming
#225

I really apreciate your explanations here. So articulate and descriptive! Thank you!

#226

1.Minimum
function min(x,y){
if(x<y) return x;
else return y;
}
2.Recursion
function isEven(n)
{
if(i==0) return true;
else if(i==1) return false;
else return isEven(n-2);
else if(i<0) return isEven(-i);
}
3.Bean Counting
function countBs(string)
let count = 0;
for(let i=0;i< string.length;i++)
if(string[i] ==“B”) {
}
}
}

#227

// First exercise recursion

function isEven(number){
  if (number < 0){
    return console.log("No negative number");
  }
  if (number == 0){
    return console.log(true);
  }
  if (number == 1){
    return console.log(false);
  }
  else{
    isEven(number - 2);
  }
}
//Test cases; odd, positive, odd, negative(not ok)
function testCases(){
  isEven(12283);
  isEven(0);
  isEven(1);
  isEven(-4);
}
testCases();

// Second exercise Bean Counting

function countBs(countString){
var letter = 0;
var countB = 0;
while(letter < countString.length){
if (countString[letter] == “B”){
countB++;
}
letter++;
}
return console.log(“The word: " + countString+” has:"+ countB);
};

function countChar(countString, countChar){
var atLetter = 0;
var numChar = 0;
while(atLetter < countString.length){
if (countString[atLetter] == countChar){
numChar++;
}
atLetter++;
}
return console.log(“The word: " + countString+” has:"+ numChar + " of character " + countChar);
}

function testCases(){
//Test for Counting Bs
countBs(“hBBBBiBBB”);
countBs(“B”);
countBs(“Hello”);
countBs(“b”);
countBs("");
console.log("--------------------------")
console.log(“Heading to second function”)

// Test cases for counting chosen letter and word
countChar(“hBBBBiBBB”,“i”);
countChar(“ushda”,“A”);
countChar(“AushdAAAAA”,“A”);
countChar(“ushda”,"");
countChar("",“A”);
countChar("","")
}
testCases()

#228

Exercise #1
I used a ternary operator on this one. And played a lot with string inn this series of exercises using the document.write statement.

<script type="text/javascript">

      function smallest (x, y) {return (x < y) ? x : y};

      //doesnt work with prompt function
      document.write(smallest(10, 5) + "<br> <p>" +
      "Is the smallest number" +
      "</p>");

</script>

Exercises 2
I first tried to make the function using a switch case structure but I ended up receiving the Call Stack is full so i converted to if else if structure.

<script type="text/javascript">

      function isEven(N) {
        if (N < 0) {
          return "N must be a positive number"
        } else if (N.toString().indexOf(".") > -1) {
          return "N must be a whole number!";
        } else if (N === 0) {
          return true
        } else if (N === 1) {
          return false
        } else {
          return isEven(N - 2);
        };
      }

      document.write(isEven(prompt("A number")));
</script>

Exercise #3
In this exercise I experimented a bit using the prompt JS function to make my countChars function as abstract as possible.

<script type="text/javascript">

      let string1 = "Good, Better, Beast. Never let it rest until your good is better and your better is best!";

      //This function search for a given character in a given string
      function countChars(char, str) {
        let count = 0;

        for (var letter in str) {
          if (str[letter] === char) {
            count++;
          } else continue;
        }
        return count;
      }


      //This function search for B character in the str string.
      function countBs() {
        return countChars("B", string1);
      }

      document.write("<p>"+
        "Counting B occurence in: "+
        "Good, Better, Beast. Never let it rest until your good is better and your better is best!<br />"+
        "There is "+
        countBs() +
        " in the string"+
        "</p>"
      );

      document.write("<p> Counting the given char in given string. <br />"+
        "The count is: <br />"+
        countChars(prompt("Provide a character to search for"), prompt("And a sring to search in."))+
        "</p>"
      );
</script>
1 Like
#229

1-minimum function
function min (a,b) {
if (a<b) return a;
else return b;
}
console.log (min( 9, 7));

2-recursion
function isEven(n) {
if (n == 0) return true;
else if (n == 1) return false;
else if (n < 0) return isEven(-n);
else return isEven(n - 2);
} console.log (isEven(50));

3-Bean counting

#230

Exercise 1
Pretty simple to do. Didn’t have too much trouble.

//Function with 2 variables “x” and “y”.
function min (x,y) {
//Checks if “x” is smaller than “y”. If yes then return “x”.
if (x<y) {
return (x);
}
//Else return “y”.
else {
return (y);
}

}
//Calling the funcions.
console.log(min(0,10));
console.log(min(0,-10))

Exercise 2
Took me some time but still wasn’t too hard.

//Takes a number.
function isEven(x) {
//Infinite loop.
for (infcounter = 1; infcounter < 2;) {
//Checks if “x” is 0. Even.
if (x===0) {
return (“true”);
break;
}
//Checks if “x” is 1. Odd.
if (x===1) {
return (“false”);
break;
}
//Checks if “x” is smaller then 0 in order to know if the function should add or substract 2.
if (x>0) {
x=x-2;
}
else {
x=x+2;
}

  }
}
//Calling the function.
console.log(isEven(50));
console.log(isEven(75));
console.log(isEven(-1));

Exercise 3
Took me a bit more time than others.

//Takes “x” input (string) and “y” input (character).
function countChar(x,y) {
//Defining and setting the count variable to 0. (Result).
var count = 0
//Defining the “y” input as a variable named “char”.
var char = y;
//Making a loop depending on the “x” input length.
for (numcount = 0; numcount < x.length; numcount = numcount +1)
//Checking each character in the sting if it matches the “y” input.
if (x[numcount]===char) {
//If yes then add 1 to the “count” a.k.a. our result.
count = count + 1;
}
return count;
}
//Takes “x” input (sring) but forces the other value “y” to be “B”.
function countBs(x) {
return countChar(x,“B”)
}
//Calling both functions.
console.log(countBs(“BBC”))
console.log(countChar(“kakkerlak”, “k”));

#231 
 <script>
        function min(x, y) {
            return Math.min(x, y);
        }

        console.log(min(20, 100));

    </script>

<script>
        function isEven(x) {
            if (x === 0){
                return true;
            } else if (x === 1 || x === -1){
                return false;
            } else if (x < 0){
                return isEven(x + 2);
            } else {
                return isEven(x - 2); // || isEven(x + 2);
            }
        }
        console.log(isEven(50));
        console.log(isEven(75));
        console.log(isEven(-1));
        console.log(isEven(-2));
        console.log(isEven(-50));
        console.log(isEven(-75));
    </script>

<script>
        function countBs(string) {
            let bsCounter = 0;
            for (let counter = 0; counter<string.length; counter++){
                if (string[counter] === "B"){
                    bsCounter++;
                }
            }
            return bsCounter;
        }
        
        function countChar(string, letter) {
            let bsCounter = 0;
            for (let counter = 0; counter<string.length; counter++){
                if (string[counter] === letter){
                    bsCounter++;
                }
            }
            return bsCounter;
        }

        console.log(countBs("BBB"));
        console.log(countChar("DoubleDee", "e"));
    </script>
#232

Minimum
function min (a, b){
if (a > b){
return a }
else {return b
}
}

console.log (min (4, 10));

#233

Recursion
function evenOdd(N){
if (N % 2 == 0) {
console.log (“even”);
} else {
console.log (“odd”);
}}

console.log(evenOdd(12));
…
Though this code produces ‘even’ or ‘odd’ Boolean outputs, it did not utilize a recursive function, nor did I ever use N = N -2 (I think that’s what he was describing in the third point). Going to look through other people’s code and see how they did it.

#234

Bean counting
var names = “the quick Brown fox jumps over the Big lazy dog named Ben near Buddy and Bobby”;
count = 0;
for(var i = 0; i < names.length; i++) {
if(names.charAt(i) === ‘B’){
count++;
}
}
…
Got it to work, but it’s not a function, the letter can even be changed as well. Going to look through other people’s code to see how to do it via function.

#235

1. Minimum Function
Function min(x, y) {
if (x < y){
return x;
else return y;
}
}
Console.log(min(1, 11));

2. Recursion
function isEven(n) {
if (n == 0) return true;
else if (n == 1) return false;
else if (n < 0) return isEven(-n);
else return isEven(n - 2);
}

3. B counting
function countBs(string)
{
let count = 0;
for (let i = 0; i < string.length; i++){
if (string[i] == “B”) {
count += 1;
}
}
}

function countChar(string, char) {
let count = 0;
for (let i = 0; i < string.length; i++) {
if (string[i] == char) {
count += 1;
}
}
return counted;
}

function countBs(string) {
return countChar(string, “B”);
}

#236

Excercise 1.
//Write a function min that takes two arguments and returns their minimum

function min(a,b) {
if (a<b){
document.write(a);
}
else {
document.write(b);
}
}

var answer = min(12,7);

//Excercise 2. I had to look up the answer and work backwards.

function test(a) {
if (a === 0){
return true;
} else if (a === 1 || a === -1){
return false;
} else if (a < 0){
return test(a + 2);
} else {
return test(a - 2);
}
}

document.write(test(0) + “
”);
document.write(test(-1) + “
”);
document.write(test(1) + “
”);
document.write(test(50) + “
”);
document.write(test(-50) + “
”);
document.write(test(-75) + “
”);

//Excercise 3. I again had to look up the answer, once I understood how ‘.length’ and ‘.charAt’ worked it made sense.

function countBs(str) {
var count = 0;
for (var i = 0; i < str.length; i++) { //the ‘.length’ in an array will return the nr of elements within it.
if (str.charAt(i) === “B”) { // the ‘.charAt()’ returns the character at a specified index.
count++;

    }
}
    return (count); // return outside of for loop

}

console.log(countBs(“BvBBC”));

//This gives the number of ‘Bs’ in the string

function countChar(str, srch) {
var count = 0;
for (var i = 0; i < str.length; i++) {
if (str.charAt(i) === srch) { // use the variable srch instead of the string “char”
count++;
}
}
return (count); // return outside of the for loop
}
console.log(countChar(“Beasts and Braves flock Bewilderingly”, “B”));

#237

function minimum(x , y){
if(x < y){
return x;
}else{return y};
} console.log(minimum(2,1));

function isEven(x){
if(x % 2 == 0){
return “Even”;
}else{return “Odd”;
}
} console.log(isEven(106));

function isEven(n){
if(n == 0){
return “Even”;
}else if(n == 1){return “Odd”;
}else if (n < 0) {return isEven(-n);
}else{return isEven (n - 2);};
} console.log(isEven(3));

function countBs(string){
var numBs= 0;
for(x= 0; x < string.length; x++){
if(string[x] == “B”){
numBs++;
}
} return numBs;
} console.log(countBs(“How many B`s Bonehead before Breakfast?”));

function countChar(string , char){
var count= 0;
for(var x= 0; x < string.length; x++){
if(string[x] == char){
count++;
}
} return count;
} console.log(countChar(“How many B`s Bonehead before Breakfast?” , “B”));

#238

Minimum
function min(x,y){
if(x<y){
return x;
} else {
return y;
}
}
console.log(min(99999,6));
Recursion
function isEven(n){
if (n==0) return true;
else if(n == 1) return false;
else if (n<0) return isEven(-n);
else return isEven (n-2);
}
console.log(isEven(-1));
Beans Counting
function countBs(myStr){
return countChar(myStr, ‘B’);
}
function countChar(myStr, character){
let count = 0;
while (myStr.length > 0){
if (myStr.charAt(0)==character) count++;
myStr = myStr.substr(1);
}
return count;
}
console.log(countBs(“ajfhB B jiisdig BBB dg”));
console.log(countChar(“saghbfsdkjgblakfds”, ‘s’));

#239

Exercise 1 Mininum

console.log(Math.min(2,8) + 100);

Exercise 2 Recursion
function isEven(n){
if(n == 0){
return true;
}
else if (n == 1){
return false;
}
else if (n < 0) {
return isEven(-n);
}
else {
return isEven(n - 2);
}

}

console.log(isEven(-2));

Exercise 3 Bean Counting
function countBs(str){
var x = str.length;
var count = 0;
var letter;

  for(var i = 0; i < x; i++){
    letter = str[i]

    if(letter == "B") {
      count++;
    }
  }
  return count;
}
alert(countBs("BrB Beaches"));
#240

1---------------->
function min(x, y){
if(x>y){
return (y);
}else{
return (x);
}
}
//END OF FUCTION, CALL AND LOG IS NOT PART OF THE FUNCTION
var Lowest = min(100, 5)
console.log Lowest

2------------------->
function isEven(x){
//HINT NEEDED FOR DEALING WITH NEGATIVES
x = Math.abs(x);
if (x == 0){
return true;
}else if (x == 1){
return false;
}else{
return isEven(x - 2);
}
}
var answer = isEven(-67)
console.log (answer)

3------------------------>
//STRUGGLED WITH THIS FOR A WHILE…
function countBs(string, char){
var counter = 0;
for (var x = 0; x < string.length; x++){
if (string[x] == char){
counter++;}
}
return counter;
}

  var Total = countBs("BRRRRRRRRRRRRRRRRRRRRBB", "R")
  console.log (Total)
#241

1:
function min (x, y) {
if (x > y) { return (y); }
else { return (x);}
}

2:
function isEven(no) {
if (no < 0) {return (isEven(-no)); }
if (no == 0) { return (true); }
if (no == 1) { return (false); }
return (isEven(no-2));
}

3:
function countChar (string, char) {
var count = 0;
for (var i = 0; i < string.length; i++) {
if (string[i] == char) { count++; }
}
return (count);
}

function countBs (string) {
return (countChar(string,“B”));
}

#242
  1. MINIMUM

function findMin(a,b){
if (a<b){
return(“a is the smallest”);
}
else if (a == b){
return(“numbers are equal”);
}
else {
return(“b is the smallest”);
}
}
alert(findMin(5,2));

  1. RECURSION

function isEven(number) {
if (number<0){
number= -number;
}
if (number == 0){
return “Even”;
}
else if (number == 1){
return “Odd”;
}
else return isEven(number-2);
}
alert (isEven(-11));

  1. BEAN COUNTING 1 - (countBs)

function countBs(string){
let counter = 0
for (var i = 0; i<string.length; i++) {
if (string[i] == “B”) {
counter++;
}
}
return(counter);
}
document.write(countBs(“BBKing”));

  1. BEAN COUNTING 2 - (countChar)

       function countChar(string, letter){
     let counter = 0
     for (var i = 0; i<string.length; i++) {
       if (string[i] == letter) {
         counter++;
       } 
     }
     return(counter);
   }
   document.write(countChar("KaresafdasKa", "a"));
#243

Function Number 1 (Minimum)

function mini(a,b){
return a<b ? a:b;
}

Function Number 2 (Recursion)

function isEven(x) {
if (x == 0){return true;}
else if (x == 1){ return false;}
else{return x%2==0 ? true:false;}
}

Function Number 3 (Count Char)

function countChar(word, letter) {
let found = 0;
for (let i = 0; i < word.length; i++) {
if (word[i] == ch) {
found+= 1;
}
}
return found;
}

function countBs(word) {
return countChar(word, “B”);
}

#244 
// Exercise - Minimum
document.write("<h1>Problem 1 - Minimum</h1>")

function minimum(a, b){
  let rtn = 0;
  if(a>b){rtn = b;}else{rtn = a;}
  return rtn;
}

var val1 = 35;
var val2 = 9;
document.write("<h2>" + "Minimum value is: " + minimum(val1, val2) + "</h2>")

// Exercise - Recursion
document.write("<h1>Problem 2 - Recursion</h1>")

function isEven(num){
  num = Math.abs(num);
  if(num < 2){
    if(num == 0){return true;}else{return false;}
  }else{
    return isEven(num-2);
  }
}

var testNum = -3;
var display = "";
if(isEven(testNum)){display = "even.";}else{display="odd.";}
document.write("<h2>" + "The number " + testNum + " is " + display + "</h2>")

// Exercise - Bean Counting
document.write("<h1>Problem 3 - Bean Counting</h1>")

function countBs(strTest){
  var lenCount = strTest.length;
  var numOfBs = 0;
  for(var count = 0; count<lenCount; count++){
    if(strTest[count] == "B"){numOfBs+=1;}
  }
  return numOfBs;
}

function countChar(strTest, chrTest){
  let lenCount = strTest.length;
  let numOfChrs = 0;
  for(var count = 0; count<lenCount; count++){
    if(strTest[count] == chrTest){numOfChrs+=1;}
  }
  return numOfChrs;
}

var stringToTest = "Uh ooh, Big Bad O'l Baboon BOB";
var chrToTest = "o";
document.write("<h2>" + "The number of B's is: " + countBs(stringToTest) + "</h2>")
document.write("<h2>" + "The number of " + chrToTest + "'s is: " + countChar(stringToTest, chrToTest) + "</h2>")