Lecture 1: C

Question 1

programming quality standards are?

Answer 1

• correctness, or whether our code solves our problem correctly
• design, or how well-written our code is, based on how efficient and readable it is
• style, or how well-formatted our code is visually

Question 2

What is compiler?

Answer 2

• Acompiler is a program that can convert one language to another, such as source code to machine code:
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Question 3

In C,mainachieves a similar effect as the Scratch block which is

Answer 3

when green flag clicked

Question 4

there are a number of commands (Tirminal window) we might use llike:

Answer 4

• cd, for changing our current directory (folder)
• cp, for copying files and directories
• ls, for listing files in a directory
• mkdir, for making a directory
• mv, for moving (renaming) files and directories
• rm, for removing (deleting) files
• rmdir, for removing (deleting) directories

Question 5

bool is a type of data which represents

Answer 5

a Boolean expression of eithertrueorfalse

Question 6

Char is a type of data which represents

Answer 6

a single character likeaor2

Question 7

Double is a type of data which represents

Answer 7

a floating-point value with more digits than afloat

Question 8

float is a type of data which represents

Answer 8

a floating-point value, or real number with a decimal value

Question 9

int is a type of data which represents

Answer 9

integers up to a certain size, or number of bits

Question 10

long is a type of data which represents

Answer 10

integers with more bits, so they can count higher than anint

Question 11

String is a type of data that represents

Answer 11

array of characters

Question 12

Forprintf, too, there are different placeholders for each type of data, called:

Answer 12

format codes:

• %cfor chars
• %ffor floats or doubles
• %ifor ints
• %lifor long integers
• %sfor strings

Question 13

//

Answer 13

comments

Question 14

how many bits are include in int?

Answer 14

int uses 32 bits, which can only contain about four billion different values (2m psitive numbers & 2m negative numbers)

Question 15

How many equals sings should used to compare two values in C?

Answer 15

== (2)

Question 16

While Loops in C looks like?

Answer 16

while (true)
{
printf(“meow\n”);
}

Awhileloop repeats over and over as long as the expression inside is true, and sincetruewill always be true, this loop will repeat forever.

Question 17

For loops and the difference between the two types (while, for)

Answer 17

the variable created within a for loop will only be accessible within the loop. In contrast, the variablewe created outside the while loop will still be accessible after the while loop finishes.

Question 18

\n

Answer 18

new line

Question 19

When will the date change?

Answer 19

In 2038, we’ll run out of bits to track time, since many years ago some humans decided to use 32 bits as the standard number of bits to count the number of seconds since January 1st, 1970. But since a 32-bit integer can only count up to about 2billion, in 2038 we’ll also reach that limit.