Strings and Arrays Preparation

Overview

You’ve probably used strings and lists a whole bunch in your programming career, but have you ever thought about how they actually are stored in memory? It turns out that they are complicated and a great chance to think about memory more deeply!

Basic Learning Objectives

Before class, you should be able to:

• Create variables and arrays in a C program
• Identify the various functions that the string library provides
• Compare the characters in two strings for equality

Advanced Learning Objectives

After class, you should be able to:

• Explain how arrays are passed to functions
• Explain how strings and character arrays relate
• Define null-terminated
• Explain the difference between strcpy and strncpy

Resources

You should read the following in DIS:

• 1.5 Arrays and Strings
• 2.6 Strings and the String Library (don’t worry about dynamic allocation yet)

Checks

Submit answers to the following to Moodle:

• What will this print and why?

    char buffer[5] = "cats";
    buffer[2] = '\0';
    printf("\%s", buffer);
  

• Fill in the ?? in this memory diagram for the previous code after it has run:

    | ??  | ??  | ??  | ??  | ??  | 
  

• If you’d like more practice, check out these problems, but you don’t need to submit any of those answers.