Category: Math
Returns a pseudorandom number ranging from zero to max, including both zero and max in the range.
The number returned is not truly random as defined in mathematics.
Example 1
Turtle Example
dot(randomNumber(100));
Console Example
console.log(randomNumber(3)); // generates a pseudorandom number in the range of 0 to 3 and then prints // it to the console
Example 2
Turtle Example -- move forward 25 times, turning right a random number of degrees between 0 and 45.
for (var i = 0; i < 25; i++) { moveForward(); turnRight(randomNumber(45)); }
This example prints out 10 pseudorandom numbers (in the range 0 to 10) to the console.
for (var i = 0; i < 10; i++) { // repeats the code inside of this block 10 times console.log(randomNumber(10)); // calculates a pseudorandom number in the range 0 to 10 // and then prints it to the console }
Example 3
This example calculates 500 pseudorandom numbers in the range 0 to 5 and then creates a bar graph illustrating the occurrences of each number.
textLabel("zero", "zero: ", "forId"); // creates a "zero" text label textLabel("one", "one: ", "forId"); // creates a "one" text label textLabel("two", "two: ", "forId"); // creates a "two" text label textLabel("three", "three: ", "forId"); // creates a "three" text label textLabel("four", "four: ", "forId"); // creates a "four" text label textLabel("five", "five: ", "forId"); // creates a "five" text label var values = [0, 0, 0, 0, 0, 0]; // creates an array to hold the occurrences of each // pseudorandom value for (var i = 0; i < 500; i++) { // repeats the code in this block 500 times values[randomNumber(5)]++; // calculates a pseudorandom number in the range 1-5, and then // increments the corresponding value in the array } hide(); // hides the turtle so it is no longer visible penWidth(5); // sets the pen width to 5 pixels turnRight(90); // turns the turtle 90 pixels to the right for (var i = 0; i < 6; i++) { // repeats the code in this block 6 times penUp(); // stops the turtle from leaving a trail behind it as it moves moveTo(50, 10 + i * 25); // moves the turtle to the correct position penDown(); // starts leaving a trail behind the turtle as it moves moveForward(values[i]); // moves the turtle forward the corresponding value in the array }
randomNumber(max);
Name | Type | Required? | Description |
---|---|---|---|
max | number | Yes | The maximum number returned |
Returns a pseudorandom number in the range of 0 to max (inclusive). For example, if a 3 is passed to the function, it could return a 0, 1, 2, or 3. The number returned will always be an integer.
Found a bug in the documentation? Let us know at documentation@code.org
Found a bug in the documentation? Let us know at documentation@code.org