Add js string codebytes (#2580)

* js codebyte added for charAt

* js code bytes added for concat

* type fixed in charAt js codebyte

* js codebytes added for indexOf

* remove array codebyte example

* fixed typo

* review edits

---------

Co-authored-by: Caupolican Diaz <caupolicandiaz@gmail.com>
Co-authored-by: SSwiniarski <86081858+SSwiniarski@users.noreply.github.com>

Author: 3 people

content/javascript/concepts/strings/terms/charAt/charAt.md

@@ -16,11 +16,11 @@ Returns a single character at the specified index of a string.
 
 ## Syntax
 
-```js
+```pseudo
 string.charAt(index);
 ```
 
-`index` is a required parameter representing the index of the character you want to return.
+`index` is a required parameter representing the index of the character to be returned.
 
 ## Examples
 
@@ -45,3 +45,17 @@ const lastLetter = greeting.charAt(greeting.length - 1);
 console.log(lastLetter);
 // Output: d
 ```
+
+## Codebyte Example
+
+The following is runnable, and demonstrates the use of the `.charAt()` method:
+
+```codebyte/javascript
+const myString = 'I love JavaScript! ';
+
+// Using integer value
+console.log(myString.charAt(2));
+
+// Using decimal value that gets rounded down from 3.5 to 3
+console.log(myString.charAt(3.5));
+```

content/javascript/concepts/strings/terms/concat/concat.md

@@ -16,7 +16,7 @@ Concatenates or combines strings together.
 
 ## Syntax
 
-```js
+```pseudo
 string.concat(string_1, string_2, string_3);
 ```
 
@@ -25,18 +25,32 @@ string.concat(string_1, string_2, string_3);
 Concatenating a string:
 
 ```js
-console.log('Do you like Latte or '.concat('Cappuccino?'));
-// Output: Do you like Latte or Cappuccino?
+console.log('Would you like a latte or '.concat('cappuccino?'));
+// Output: Would you like a latte or cappuccino?
 ```
 
 ## Example 2
 
 Concatenating strings with the usage of variables:
 
 ```js
-const x = 'Do you like Latte or';
-const y = 'Cappuccino?';
+const x = 'Would you like a latte or';
+const y = 'cappuccino?';
 
 console.log('Hey Bob! '.concat(x, ' ', y));
-// Output: Hey Bob! Do you like Latte or Cappuccino?
+// Output: Hey Bob! Would you like a latte or cappuccino?
+```
+
+## Codebyte Example
+
+The following is runnable, and demonstrates the use of the `.concat()` method:
+
+```codebyte/javascript
+// Concatenating a string directly:
+console.log('I love JavaScript'.concat(' and Go'));
+
+// Concatenating strings using variables
+const myString = 'I love JavaScript '
+const myString2 = 'and Go';
+console.log(myString.concat(myString2));
 ```

content/javascript/concepts/strings/terms/indexOf/indexOf.md

@@ -1,6 +1,6 @@
 ---
 Title: '.indexOf()'
-Description: 'Searches a string for a given value and returns the first index if found. Returns -1 if not found.'
+Description: 'Searches a string for a given value and returns the first index if found.'
 Subjects:
   - 'Web Development'
   - 'Computer Science'
@@ -16,7 +16,7 @@ Searches a string for a given value and returns the first index if found. Return
 
 ## Syntax
 
-```js
+```pseudo
 string.indexOf(value, startSearch);
 ```
 
@@ -70,3 +70,18 @@ const didYouFindWaldo = people.indexOf('Waldo');
 console.log(didYouFindWaldo);
 // Output: -1
 ```
+
+## Codebyte Example
+
+The following is runnable, and demonstrates the use of the `.indexOf()` method:
+
+```codebyte/javascript
+// Declaring a string
+const myString = 'I love JavaScript! ';
+
+// Case 1: Target value exists
+console.log(myString.indexOf('love'));
+
+// Case 2: Target value does not exist
+console.log(myString.indexOf('hate'));
+```