Question

Look at the following code. What value will be stored in s after the code executes? char name[10]; int s; strcpy(name, "Jimmy"); s = strlen(name);

Short answer

Answer: The value stored in the integer variable 's' is 5.

Step-by-step solution

Declare an array and variables

First, we declare an array of characters named 'name' with a size of 10, and an integer variable 's'.

Copy the string "Jimmy"

Next, we use the 'strcpy()' function to copy the string "Jimmy" into the 'name' array. After this line of code executes, the 'name' array will contain the characters "Jimmy".

Calculate the length of the string

The 'strlen()' function is used to calculate and return the length of a string, not including the null terminator. The 'strlen()' function is applied to the 'name' array, which contains the string "Jimmy".

Store the value in the integer variable 's'

After executing 's = strlen(name)', the length of the string "Jimmy" will be stored in the integer variable 's'. The string "Jimmy" has a length of 5 characters, so 's' will be equal to 5. Finally, after executing the given code, the value stored in 's' will be 5.

Key concepts

Arrays in C++

In C++, arrays are used to store multiple items of the same type together. Think of them like a collection of boxes, where each box can hold a value. With arrays, you can easily access each item using an index. For example, in the exercise, we declared a character array 'name' with a size of 10. This means it can hold up to 10 'char' elements.

• The index always starts at zero. So, 'name[0]' is the first character.
• It’s crucial to understand the size you need. Overflows (when you try to store more than it can hold) can lead to errors.
• 'char name[10]' reserves memory for 10 characters, even if the word "Jimmy" is shorter.

The extra space is often used for a null terminator, which indicates the end of a string.

String Manipulation in C++

String manipulation refers to the various operations you can perform on strings, such as copying, concatenation, and more. In C++, these operations can be done using functions from the C++ Standard Library.
For instance, in the example, we used 'strcpy()' to copy the string "Jimmy" into the 'name' array. This function takes two parameters: the destination and the source. In this case, 'name' is the destination, and "Jimmy" is the source.

• 'strcpy()' does not check lengths, so it's important the destination array is large enough to hold the source string plus the null terminator.
• Always ensure your destination can handle the content safely to avoid errors.

String manipulation in C++ becomes powerful when combined with loops and conditions, allowing for dynamic and flexible code.

strlen Function in C++

The 'strlen()' function is used to determine the length of a string by counting the characters before the null terminator, which marks the end of the string.
In the example, after copying "Jimmy" into 'name', we used 'strlen(name)' to find its length. This length, stored in 's', is 5, as "Jimmy" has five characters.

• 'strlen()' returns a size_t type, which is an unsigned integer.
• It’s useful to validate array lengths when working with strings.
• Remember, 'strlen()' doesn't count the null terminator.

Understanding 'strlen()' helps you manage string data effectively, ensuring you read the correct amount of data and avoid mishaps with string operations.