Objectives

Control Flow & Arrays

• Define a function that accepts a sentence string and two words as args. The function should return a boolean indicating if the sentence includes either word.

  function eitherStringIncluded(sentence, word1, word2) {
    return sentence.includes(word1) || sentence.includes(word2) ? true : false;
  }

• Identify a pair of mutually exclusive conditions

  • Heads or Tails
  • True or False
  • Assessment Score >= 80 ? Pass : Fail

• Given a for loop, translate it into a while loop, and vice-versa

  function aCounter(word) {
    let index = 0;
    let count = 0;
    while (index < word.length) {
      let char = word[index];
      if (char === "a" || char === "A") {
        count += 1;
      }
      index++;
    }
    return count;
  }
  
  function aCounter(word) {
    word = word.toLowerCase();
    let count = 0;
    for (var i = 0; i < word.length; i++) {
      if (word[i] === "a") {
        count++;
        le;
      }
    }
    return count;
  }

  • Here is a quick drawing of how the delimiters are transferred in between.

• Write a function that iterates through a provided string argument

  function countVowels(word) {
    const VOWEL = "aeiou";
    let count = 0;
    for (var i = 0; i < word.length; i++) {
      if (VOWEL.indexOf(word[i]) > -1) {
        count++;
      }
    }
    return count;
  }

• Given a description of pig latin, write a function that takes in a string argument and utilizes String#slice to translate the string into pig latin.

  function pigLatinWord(word) {
    const VOWEL = "aeiou";
    if (VOWEL.indexOf(word[0]) > -1) {
      return word + "yay";
    } else {
      for (var i = 0; i < word.length; i++) {
        if (VOWEL.indexOf(word[i]) > -1) {
          return word.slice(i) + word.slice(0, i) + "ay";
        }
      }
    }
  }

• Write a function that takes in an array of words and a string as arguments and returns a boolean indicating whether the string is located inside of the array. The function must use Array.indexOf().

  function wordWithinArray(array, word) {
    return array.indexOf(word) > -1 ? true : false;
  }

• Define that an array literal is an ordered list of values defined by using bracket and individual values are read by indexing.

  • The Array is a data type that is one of JS’s global objects, they are used to store multiple values within a single structure (similar to creating a list).

  • Arrays are zero-indexed.

    let arr = ["apple", "pear", "orange"];
    // arr[0] => 'apple'
    // arr[1] => 'pear'
    // arr[2] => orange

• Prevent code that can throw an exception from causing the program to crash.
  • The most important thing to remember when writing while loops is to always be working towards your condition, if we omitted the index++ our loop would run infinitely; likely crashing w/e we were working on.
  • Types of Errors
    • FYI: This is not part of the reading/lecture, just a nice to know.
    • *Error : Most often used for implementing user defined exceptions.
    • RangeError : Generated by numbers that fall outside a specified range.
    • ReferenceError : Thrown when a non-existent variable is accessed.
    • SyntaxError : Thrown when rules of JS language are broken (i.e. forgetting to close a curly brace)
    • TypeError : Occurs when a value is not of the expected type.
    • URIError : Thrown by methods such as encodeURI() and decodeURI() when they encounter a malformed URI.
    • EvalError : Thrown when the eval() function is used improperly

• In the above list, Reference, Syntax, and Type are seen most frequently.

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