Generate a random array of integers in Java

In order to generate random array of integers in Java, we use the nextInt() method of the java.util.Random class. This returns the next random integer value from this random number generator sequence.

Declaration ? The java.util.Random.nextInt() method is declared as follows ?

public int nextInt()

Let us see a program to generate a random array of integers in Java ?

Example

<span class="kwd">import</span><span class="pln"> java</span><span class="pun">.</span><span class="pln">util</span><span class="pun">.</span><span class="typ">Random</span><span class="pun">;</span><span class="pln">
</span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">class</span><span class="pln"> </span><span class="typ">Example</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
   </span><span class="kwd">public</span><span class="pln"> </span><span class="kwd">static</span><span class="pln"> </span><span class="kwd">void</span><span class="pln"> main</span><span class="pun">(</span><span class="typ">String</span><span class="pun">[]</span><span class="pln"> args</span><span class="pun">)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
      </span><span class="typ">Random</span><span class="pln"> rd </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="typ">Random</span><span class="pun">();</span><span class="pln"> </span><span class="com">// creating Random object</span><span class="pln">
      </span><span class="kwd">int</span><span class="pun">[]</span><span class="pln"> arr </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">new</span><span class="pln"> </span><span class="kwd">int</span><span class="pun">[</span><span class="lit">5</span><span class="pun">];</span><span class="pln">
      </span><span class="kwd">for</span><span class="pln"> </span><span class="pun">(</span><span class="kwd">int</span><span class="pln"> i </span><span class="pun">=</span><span class="pln"> </span><span class="lit">0</span><span class="pun">;</span><span class="pln"> i </span><span class="pun"><</span><span class="pln"> arr</span><span class="pun">.</span><span class="pln">length</span><span class="pun">;</span><span class="pln"> i</span><span class="pun">++)</span><span class="pln"> </span><span class="pun">{</span><span class="pln">
         arr</span><span class="pun">[</span><span class="pln">i</span><span class="pun">]</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> rd</span><span class="pun">.</span><span class="pln">nextInt</span><span class="pun">();</span><span class="pln"> </span><span class="com">// storing random integers in an array</span><span class="pln">
         </span><span class="typ">System</span><span class="pun">.</span><span class="kwd">out</span><span class="pun">.</span><span class="pln">println</span><span class="pun">(</span><span class="pln">arr</span><span class="pun">[</span><span class="pln">i</span><span class="pun">]);</span><span class="pln"> </span><span class="com">// printing each array element</span><span class="pln">
      </span><span class="pun">}</span><span class="pln">
   </span><span class="pun">}</span><span class="pln">
</span><span class="pun">}</span>

Output

-1848681552
39846826
858647196
1805220077
-360491047

Note ? The output might vary on Online Compilers.

Here we use the nextInt() method in a loop to get a random integer for each element.

for (int i = 0; i < arr.length; i++)
arr[i] = rd.nextInt();