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How to generate a random number between a given range in Java
okwudili onyejiaku
Overview
In this shot, we'll see how to generate a random number in given range. Let's have a look at its syntax.
Syntax
startRange + (int) (Math.random() * ((endRange - startRange) + 1))
Syntax for getting a random number in a particular range in Java
Parameters
startRange: This is the starting point of the specified range.endRange: This is the end point of the specified range.Math.random(): This is used to generate a random value.(int): This typecasts the value we get from the product of the random number generated byMath.random()and the difference of the starting range and ending range plus one. So, if the value returned is a float or double value, it will convert it to an integer immediately.
Return value
The value returned is an integer value that is between startRange and endRange.
Example
class HelloWorld {
public static void main( String args[] ) {
// create some start ranges
int startRange1 = 5;
int startRange2 = 1;
int startRange3 = 0;
// create some end ranges
int endRange1 = 50;
int endRange2 = 10;
int endRange3 = 3;
// get the random between some ranges
int rand1 = startRange1 + (int) (Math.random() * ((endRange1 - startRange1) + 1));
int rand2 = startRange2 + (int) (Math.random() * ((endRange2 - startRange2) + 1));
int rand3 = startRange3 + (int) (Math.random() * ((endRange3 - startRange3) + 1));
// print the results
System.out.println("A Random number between "+startRange1+" and "+endRange1+" is " +rand1);
System.out.println("A Random number between "+startRange2+" and "+endRange2+" is " +rand2);
System.out.println("A Random number between "+startRange3+" and "+endRange3+" is " +rand3);
}
}Getting a random number between a given range in Java
Explanation
- Lines 4–6: We define some values that will serve as starting points for our ranges.
- Lines 9–11: We define some values that will be the end points of our ranges.
- Lines 14–16: We get some random numbers between the already defined ranges.
- Lines 19-21: We print the results to the console.
RELATED TAGS
java
range
random number
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CONTRIBUTOR
okwudili onyejiaku
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