Array workshop tidy

arrays/100.js

@@ -1,10 +1,9 @@
 // Predict and explain...
-// What will nums.length evalute to after running the code here
-// Check your prediction and explanation by running the code. Use mdn documentation for mdn to help you make your prediction
-// 
+// What will get logged to the console when running the code below?
+// Check your prediction and explanation by running the code. Use the MDN documentation for .push to help build your understanding of these outcomes
 
-const cities = ["Manchester", "London","Birmingham","Cape Town","Glasgow"];
-const result = cities.push("Liverpool","Sheffield");
+const cities = ["Manchester", "London", "Birmingham", "Cape Town", "Glasgow"];
+const result = cities.push("Liverpool", "Sheffield");
 
 console.log(`The result is ${result}`);
-console.log("cities now looks like this: ",cities);
+console.log("cities now looks like this: ", cities);

arrays/200.js

@@ -1,8 +1,8 @@
 // Predict and explain...
-// What will nums.length evalute to after running the code here
+// What will nums.length evaluate to after running the code here?
 // Check your prediction and explanation by running the code
 
-const nums = [10,3,5,6,];
+const nums = [10, 3, 5, 6];
 
 nums[6] = 50;
 

arrays/300.js

@@ -1,7 +1,6 @@
 // the head of an array is the first element of an array
 // the tail of an array is the last element of an array
 
-
 const alphabet = ['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'];
 
 function getHead(arr) {
@@ -15,5 +14,6 @@ function getTail(arr) {
 console.log(`The first letter of the alphabet is ${getHead(alphabet)}`);
 console.log(`The last letter of the alphabet is ${getTail(alphabet)}`);
 console.log(alphabet.length);
+
 // Explain why alphabet length is now 24
 // How could we change the functions we defined to return the same values, but not change the length of alphabet?

arrays/0.js → arrays/400.js

@@ -2,7 +2,6 @@
 // Try predicting and explaining what will get logged to the console when the code runs
 // To check your prediction, play computer using the Python Visualiser: https://pythontutor.com/render.html#mode=display
 
-
 const ingredients = ["olive oil","tomatoes",'garlic','onion', 'carrot'];
 let ingredientsCopy = ingredients;
 ingredientsCopy.push('pasta','salt','pepper');

arrays/500.test.js

@@ -0,0 +1,24 @@
+// list is an array that holds a mix of data types
+// we need to collect just the numbers and not the strings
+// before running the tests, make a prediction and explanation about what you expect the function to return 
+// fix anything that doesn't work
+
+function collectNumbers(list) {
+    const numbersOnly = [];
+    for (const item of list) {
+        if (item === 'string') {
+            numbersOnly.push(item);
+        }
+    }
+    return numbersOnly;
+}
+
+// NOTE: you do not need to change anything in the test
+test('only collects numbers in the array',() => {
+    const currentOutput = collectNumbers([10.1,"hello",6.1,8.0, 9.7, 10.1,"hi", 3.5,"oops"]);
+    const targetOutput = [10.1,6.1,8.0, 9.7, 10.1, 3.5,];
+
+    expect(currentOutput).toEqual(targetOutput);
+});
+
+

arrays/600.test.js

@@ -1,26 +1,15 @@
-
-
-// list is an array that holds a mix of data types
-// we need to collect just the numbers and not the strings
-// before runnning the tests, make a prediction and explanation about what you expect the function to return 
-// fix anything that doesn't work
-
-function collectNumbers(list) {
-
-    const numbersOnly = [];
-    for (const item of list) {
-        if (item === 'string') {
-            numbersOnly.push(item);
-        }
-    }
-    return numbersOnly;
+// Predict and explain...
+// Below is a function countWords and a test that checks that it counts the words in a string correctly
+// At the moment, it isn't working. Try to reason about what happens when the function is called.
+// Check your prediction and explanation using the test
+// Fix anything that doesn't work
+
+function countWords(text) {
+    return text.split('').length;
 }
 
-test('only collects numbers in the array',() => {
-    const currentOutput = collectNumbers([10.1,"hello",6.1,8.0, 9.7, 10.1,"hi", 3.5,"oops"]);
-    const targetOutput = [10.1,6.1,8.0, 9.7, 10.1, 3.5,];
-
-    expect(currentOutput).toEqual(targetOutput);
-});
-
-
+// NOTE: you do not need to change anything in the test
+test('should count the words in a string of text', () => {
+    const text = "Here is a plain sentence with some information! Try to find the word count";
+    expect(countWords(text)).toBe(14);
+});

arrays/700.js

@@ -0,0 +1,21 @@
+// Predict and explain...
+// We've seen for..of loops used for arrays.
+// Below we try to use it with a variable which isn't an array.
+// What do you think will get logged?
+// Don't run the code until you've predicted and explained the whole file.
+// Then check your prediction and explanation by running the code
+
+const sentence = "I really enjoy ice cream";
+
+for (const part of sentence) {
+    console.log(part);
+}
+
+// What's the difference between what was written above, and what's below?
+// How will they behave differently?
+
+const parts = sentence.split(" ");
+
+for (const part of parts) {
+    console.log(part);
+}

arrays/800.js

@@ -1,21 +1,37 @@
-// Predict and explain...
-// We've seen for..of loops used for arrays.
-// Below we try to use it with a variable which isn't an array.
-// What do you think will get logged?
-// Don't run the code until you've predicted and explained the whole file.
-// Then check your prediction and explanation by running the code
+// Below, we have two functions which have the same aim.
+// Both functions take a word as a parameter.
+// If the function has been called with that word before (regardless of case), the previous version of the word is returned.
+// So if you called the function with "hello", then "HELLO", the second call will return "hello".
+// If the word has not been used before, it will just be returned as-is.
 
-const sentence = "I really enjoy ice cream";
+// One of these functions has side-effects.
+// When you call it, it does something other than just returning a value based only on its parameters.
+//
+// The other doesn't have side effects.
+// When you call it with the same arguments, it always does exactly the same thing,
+// and you can see everything it does in its return value.
+//
+// Which function has side-effects? Which doesn't?
+// Try to write tests for both functions.
+// Which was easier to test? What issues did you run into writing tests?
 
-for (const part of sentence) {
-    console.log(part);
-}
-
-// What's the difference between what was written above, and what's below?
-// How will they behave differently?
+const previousWords = [];
 
-const parts = sentence.split(" ");
+function getPreviousCaseOfWordOne(word) {
+    for (const previousWord of previousWords) {
+        if (previousWord.toLowerCase() === word.toLowerCase()) {
+            return previousWord;
+        }
+    }
+    previousWords.push(word);
+    return word;
+}
 
-for (const part of parts) {
-    console.log(part);
+function getPreviousCaseOfWordTwo(word, words) {
+    for (const previousWord of words) {
+        if (previousWord.toLowerCase() === word.toLowerCase()) {
+            return previousWord;
+        }
+    }
+    return word;
 }