2.2.3 Additional Programming Techniques

• What is an array in programming?

  An array is a static data structure that can hold a fixed number of data elements.
• What must each data element in an array be?

  Each data element must be of the same data type.
• How are elements in an array identified?

  The elements in an array are identified by an index number.
• What is the index of the first element in an array?

  The first element in an array always has an index of 0.
• What is the purpose of pseudo code in relation to arrays?

  Pseudo code is used to manipulate arrays to traverse, add, remove, and search data.
• How can you traverse an array in Python?

  You can use a for loop to display each data element in order.
• Can you insert new values into an array?

  No, you cannot insert new values into an array since its size is fixed.
• What happens when you overwrite the fourth element in an array?

  Overwriting the fourth element changes its value to the new value provided.
• How can you delete a value in an array?

  You can overwrite it with a blank space to make it appear deleted.
• How do you search for a specific value in a large array?

  A for loop is needed to search through each element for a specific value.
• What is a two-dimensional array?

  A two-dimensional array is a data structure that can have multiple rows and columns.
• How is indexing done in a two-dimensional array?

  Indexing in a two-dimensional array uses two values: row and column.
• How do you print a specific data element in a two-dimensional array?

  You can use the index number to access and print the specific data element.
• How do you search for a specific value in a two-dimensional array?

  You need two for loops: one for the row and another for the values of each row.
• What is a record in programming?

  A record can store data of different data types.
• What is a field in a record?

  A field is each piece of information in the record.
• What is a key field in a record?

  A key field is unique data that identifies each record.
• Why is a Student ID a good key field for a student record?

  Because no two students can have the same Student ID.
• What does SQL stand for?

  SQL stands for Structured Query Language.
• What is the purpose of SQL?

  SQL is used to search for data in a database.
• What is the format of an SQL statement?

  The format is: SELECT field1, field2, field3… FROM table WHERE criteria.
• Write an SQL statement to display the make and colour for cars that are grey or blue.

  SELECT Make, Colour FROM Cars WHERE Colour = 'grey' OR Colour = 'blue'.
• Write an SQL statement to display all fields for cars that are 10 years old or less.

  SELECT * FROM Cars WHERE Age <= 10.
• What are the differences between a 1D array, 2D array, and record?

  • 1D Array: Holds a fixed number of elements of the same data type.
  • 2D Array: Holds multiple rows and columns of the same data type.
  • Record: Can store different data types and consists of fields with a unique key field.
• What are the steps to manipulate arrays in Python?

  1. Traverse: Use a for loop to display elements.
  2. Insert: Change existing values (cannot add new).
  3. Delete: Overwrite with a blank space.
  4. Search: Use a for loop to find specific values.
• What is the role of wildcards in SQL?

  • Wildcards are symbols used to substitute characters.
  • The * symbol represents ALL fields.