Kotlin Program to Display All Prime Numbers from 1 to N

In this article, we will understand how to display all the prime numbers from 1 to N in Kotlin. All possible positive numbers from 1 to infinity are called natural numbers. Prime numbers are special numbers who have only two factors 1 and itself and cannot be divided by any other number.

Below is a demonstration of the same

Suppose our input is ?

Value of n :10

The desired output would be ?

2 3 5 7

Algorithm

• Step 1 ? Start

• Step 2 ? Declare two integers: low and high

• Step 3 ? Define the integer

• Step 4 ? Using a while loop from low to high, check if the ?i? value is divisible by any number from 2 to i.

• Step 5 ? If yes, check the next number

• Step 6 ? If no, store the number as a prime number

• Step 7 ? Display the ?i? value as LCM of the two numbers

• Step 8 ? Stop

Example 1

In this example, we will display all Prime Numbers from 1 to N in Kotlin using a for loop:

<div class="execute"></div><div class="code-mirror  language-kotlin" contenteditable="plaintext-only" spellcheck="false" style="outline: none; overflow-wrap: break-word; overflow-y: auto; white-space: pre-wrap;"><span class="token keyword">fun</span> <span class="token function">main</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
   <span class="token keyword">var</span> low <span class="token operator">=</span> <span class="token number">1</span>
   <span class="token keyword">val</span> input <span class="token operator">=</span> <span class="token number">15</span>

   <span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"The value of N is defined as <span class="token interpolation variable">$input</span>"</span><span class="token punctuation">)</span>
   <span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"The prime numbers are: "</span><span class="token punctuation">)</span>

   <span class="token keyword">while</span> <span class="token punctuation">(</span>low <span class="token operator"><</span> input<span class="token punctuation">)</span> <span class="token punctuation">{</span>
      <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token function">primeNumber</span><span class="token punctuation">(</span>low<span class="token punctuation">)</span><span class="token punctuation">)</span>
         <span class="token function">print</span><span class="token punctuation">(</span>low<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token string">" "</span><span class="token punctuation">)</span>
      <span class="token operator">++</span>low
   <span class="token punctuation">}</span>
<span class="token punctuation">}</span>

<span class="token keyword">fun</span> <span class="token function">primeNumber</span><span class="token punctuation">(</span>num<span class="token operator">:</span> Int<span class="token punctuation">)</span><span class="token operator">:</span> Boolean <span class="token punctuation">{</span>
   <span class="token keyword">var</span> flag <span class="token operator">=</span> <span class="token boolean">true</span>
   <span class="token keyword">for</span> <span class="token punctuation">(</span>i <span class="token keyword">in</span> <span class="token number">2</span><span class="token operator">..</span>num <span class="token operator">/</span> <span class="token number">2</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
      <span class="token keyword">if</span> <span class="token punctuation">(</span>num <span class="token operator">%</span> i <span class="token operator">==</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
         flag <span class="token operator">=</span> <span class="token boolean">false</span>
         <span class="token keyword">break</span>
      <span class="token punctuation">}</span>
   <span class="token punctuation">}</span>
   <span class="token keyword">return</span> flag
<span class="token punctuation">}</span>
</div><div class="output-wrapper"><div class="console-close"></div><div class="code-output"></div></div>

Output

The value of N is defined as 15
The prime numbers are:
1 2 3 5 7 11 13

Example 2

In this example, we will display all Prime Numbers from 1 to N ?

<div class="execute"></div><div class="code-mirror  language-kotlin" contenteditable="plaintext-only" spellcheck="false" style="outline: none; overflow-wrap: break-word; overflow-y: auto; white-space: pre-wrap;"><span class="token keyword">fun</span> <span class="token function">main</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
   <span class="token keyword">val</span> input <span class="token operator">=</span> <span class="token number">10</span>
   <span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"The value of N is defined as <span class="token interpolation variable">$input</span>"</span><span class="token punctuation">)</span>
   <span class="token function">printPrimeNumbers</span><span class="token punctuation">(</span>input<span class="token punctuation">)</span>
<span class="token punctuation">}</span>

<span class="token keyword">fun</span> <span class="token function">printPrimeNumbers</span><span class="token punctuation">(</span>input<span class="token operator">:</span> Int<span class="token punctuation">)</span> <span class="token punctuation">{</span>
   <span class="token keyword">var</span> low <span class="token operator">=</span> <span class="token number">1</span>
   <span class="token function">println</span><span class="token punctuation">(</span><span class="token string">"The prime numbers are: "</span><span class="token punctuation">)</span>
   <span class="token keyword">while</span> <span class="token punctuation">(</span>low <span class="token operator"><</span> input<span class="token punctuation">)</span> <span class="token punctuation">{</span>
      <span class="token keyword">if</span> <span class="token punctuation">(</span><span class="token function">primeNumber</span><span class="token punctuation">(</span>low<span class="token punctuation">)</span><span class="token punctuation">)</span>
         <span class="token function">print</span><span class="token punctuation">(</span>low<span class="token punctuation">.</span><span class="token function">toString</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">+</span> <span class="token string">" "</span><span class="token punctuation">)</span>
      <span class="token operator">++</span>low
   <span class="token punctuation">}</span>
<span class="token punctuation">}</span>

<span class="token keyword">fun</span> <span class="token function">primeNumber</span><span class="token punctuation">(</span>num<span class="token operator">:</span> Int<span class="token punctuation">)</span><span class="token operator">:</span> Boolean <span class="token punctuation">{</span>
   <span class="token keyword">var</span> flag <span class="token operator">=</span> <span class="token boolean">true</span>
   <span class="token keyword">for</span> <span class="token punctuation">(</span>i <span class="token keyword">in</span> <span class="token number">2</span><span class="token operator">..</span>num <span class="token operator">/</span> <span class="token number">2</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
      <span class="token keyword">if</span> <span class="token punctuation">(</span>num <span class="token operator">%</span> i <span class="token operator">==</span> <span class="token number">0</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
         flag <span class="token operator">=</span> <span class="token boolean">false</span>
         <span class="token keyword">break</span>
      <span class="token punctuation">}</span>
   <span class="token punctuation">}</span>
   <span class="token keyword">return</span> flag
<span class="token punctuation">}</span>
</div><div class="output-wrapper"><div class="console-close"></div><div class="code-output"></div></div>

Output

The value of N is defined as 10
The prime numbers are:
1 2 3 5 7