Flash cards
Review the key moves
What is the main idea behind C++ How To Generate Random Numbers?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
___ << rand();Put the learning moves in the order that makes the concept easiest to apply.
Random Number
You can use the rand() function, found in the <cstdlib> library, to generate a random number:
Example
cout << rand();To get more control over the random number, for example, if you only want a random number between 0 and 100, you can use the following formula:
Example
// Generate a random number between 0 and 100 int randomNum = rand() % 101; cout << randomNum;
return 0;Note
The examples above just outputs a random number once. They don't output different random numbers each time the program runs. To fix this, you can use the srand() function and add the time() function from the <ctime> library.
This will generate a random number from 0 to 100 each time the program runs:
Example
// Get a different random number each time the program runs srand(time(0)); // Generate a random number between 0 and 100 int randomNum = rand() % 101; cout << randomNum;
return 0;