Teacher code

A timetable friendly name.

Try

Select the button below to open the C# program in a new window. Run the program and read the lines of code to see if you can understand how it works. It will be helpful to arrange your display so that you can have this browser window on one side of the screen and the code on the other.

GDB MAIN

Watch this video to learn about the new concepts shown in the program:

Knowledge Organiser

Strings are zero indexed sequences of characters that behave like an array of characters. Therefore you can index them like this:

string word = "Hello";

Console.WriteLine(word[1]);

This code would output the letter "e". The number 1 can be replaced with a variable. Be careful not to reference an index longer than the number of characters in the string minus one.

The new commands used in this program and others that may be useful. Select them below to learn more:

x is assigned the index of the first instance of string z in string y. Returns -1 if the string is not found.

Returns a string within x starting from index y (inclusive) to z (exclusive).

x is assigned to be the string w with all instances of string y replaced with string z.

x is assigned to be a string concatenated from all elements of array z separated by string y.

x is assigned to be a new list from string y separated every time string z occurs in y.

x is assigned to be string y with all leading and trailing optional characters z removed. If not specified, whitespace and hidden escape characters will be removed.

x = x.Trim()

Would remove any white space or escape characters at the beginning or end of string x.

x is assigned to be the string y, z times. E.g.

string x = new string("@", 5)

Would result in x = "@@@@@"

Investigate

Questions to think about with this program to check your understanding:

What is the purpose of line 14:

int space = teacher.IndexOf(" ");

REVEAL ANSWER

To find the index of where the space is in the teacher string. You need to know where the space is so that you can extract the next two letters.

What is the reason for using `space + 1` and `2` in line 15?

REVEAL ANSWER

`space + 1` is the index of the first character after the space. `2` means return two characters after the space.

Make

Success Criteria

Change the program so that:

The user can enter the number of letters to output.
An apostrophe in the name is removed.

GDB MAIN

Typical inputs and outputs from the program would be:

Enter the name of the teacher: john smith

How many letters: 3

JSM

Enter the name of the teacher: john smith

How many letters: 5

JSMIT

Enter the name of the teacher: Dave O'Loughlin

How many letters: 4

DOLO

Help

Use the flowcharts if you need more support in understanding the steps required to meet the criteria. Use the Parsons code sorting exercise only if you are really stuck.