Swift Program to Check if two of three boolean variables are true

This tutorial will discuss how to write a Swift program to check if two of three boolean variables are true.

Given three boolean values now we have to check if two of the boolean variables are true or not. Boolean variables are those variables that either contain true or false. We can also use this program to check, out of given three conditions two are true or not.

Below is a demonstration of the same ?

Suppose we enter the following input ?

<span class="typ">Value1</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">true</span><span class="pln">
</span><span class="typ">Value2</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">true</span><span class="pln">
</span><span class="typ">Value3</span><span class="pln"> </span><span class="pun">=</span><span class="pln"> </span><span class="kwd">false</span>

Following is the desired output ?

Two of the three variables are true

Algorithm

Following is The algorithm to check if two of three boolean variables are true ?

• Step 1 ? Create three variables with predefined boolean values or with user-defined boolean values named as "num1", "num2", and "num3".

• Step 2 ? Create another bool type variable that stores the final result named "res1".

• Step 4 ? Using if-else statement, compare the three values with each other using || and && operators and store the result in the "res1" variable.

• Step 5 ? If the two variables are true out of three variable, then display "Two of the three variables are true". Otherwise display "Two of the three variables are not true".

Example 1

The following program shows how to check if two of three boolean variables are true.

<div class="execute"></div><div class="code-mirror  language-swift" contenteditable="plaintext-only" spellcheck="false" style="outline: none; overflow-wrap: break-word; overflow-y: auto; white-space: pre-wrap;"><span class="token keyword">import</span> <span class="token class-name">Foundation</span>
<span class="token keyword">import</span> <span class="token class-name">Glibc</span>

<span class="token keyword">var</span> num1 <span class="token operator">=</span> <span class="token boolean">true</span>
<span class="token keyword">var</span> num2 <span class="token operator">=</span> <span class="token boolean">true</span>
<span class="token keyword">var</span> num3 <span class="token operator">=</span> <span class="token boolean">false</span>
<span class="token keyword">var</span> res1 <span class="token punctuation">:</span> <span class="token class-name">Bool</span>

<span class="token keyword">if</span> <span class="token punctuation">(</span>num1<span class="token punctuation">)</span><span class="token punctuation">{</span>
   <span class="token comment">// If num1 is true and either num2 or num3 is true</span>
   <span class="token comment">// then res1 is true</span>
   res1 <span class="token operator">=</span> num2 <span class="token operator">||</span> num3
<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
   <span class="token comment">// If num1 is false and both </span>
   <span class="token comment">// num2 and num3 is true then the</span>
   <span class="token comment">// res1 is also true</span>
   res1 <span class="token operator">=</span> num2 <span class="token operator">&&</span> num3
<span class="token punctuation">}</span>
<span class="token keyword">if</span> <span class="token punctuation">(</span>res1<span class="token punctuation">)</span><span class="token punctuation">{</span>
   <span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Two of the three variables are true"</span></span><span class="token punctuation">)</span>
<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
   <span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Two of the three variables are not true"</span></span><span class="token punctuation">)</span>
<span class="token punctuation">}</span>
</div><div class="output-wrapper"><div class="console-close"></div><div class="code-output"></div></div>

Output

Two of the three variables are true

Here in the above code, we create three bool type variable with values named as "num1 = true", "num2 = true", and "num3 = false". Now we use if statement to compare the three variables with each and store the result in the "res1" variable as shown in the below code ?

<span class="kwd">if</span><span class="pln"> </span><span class="pun">(</span><span class="pln">num1</span><span class="pun">) </span><span class="pun">{</span><span class="pln">
   res1 </span><span class="pun">=</span><span class="pln"> num2 </span><span class="pun">||</span><span class="pln"> num3
</span><span class="pun">} </span><span class="kwd">else </span><span class="pun">{</span><span class="pln">
   res1 </span><span class="pun">=</span><span class="pln"> num2 </span><span class="pun">&&</span><span class="pln"> num3
</span><span class="pun">}</span>

Here, we will check if num1 is true, then the res1 should be true if either num2 or num3 is true. Otherwise, if num1 is false, then res1 will be true when both num2 and num3 are true. Here, num1 and num2 both are true so the output will be "Two of the three variables are true".

Example 2

The following program shows how to check if two of three boolean variables are true.

<div class="code-mirror  language-swift" contenteditable="plaintext-only" spellcheck="false" style="outline: none; overflow-wrap: break-word; overflow-y: auto; white-space: pre-wrap;"><span class="token keyword">import</span> <span class="token class-name">Foundation</span>
<span class="token keyword">import</span> <span class="token class-name">Glibc</span>

<span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Enter the value of variables either true or false"</span></span><span class="token punctuation">)</span>
<span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Variable 1-"</span></span><span class="token punctuation">)</span>

<span class="token comment">// Reading the input from the user and convert them into boolean type</span>
<span class="token keyword">var</span> num1 <span class="token operator">=</span> <span class="token class-name">Bool</span><span class="token punctuation">(</span><span class="token function">readLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">!</span><span class="token punctuation">)</span><span class="token operator">!</span>
<span class="token function">print</span><span class="token punctuation">(</span>num1<span class="token punctuation">)</span>
<span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Variable 2-"</span></span><span class="token punctuation">)</span>
<span class="token keyword">var</span> num2 <span class="token operator">=</span> <span class="token class-name">Bool</span><span class="token punctuation">(</span><span class="token function">readLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">!</span><span class="token punctuation">)</span><span class="token operator">!</span>
<span class="token function">print</span><span class="token punctuation">(</span>num2<span class="token punctuation">)</span>
<span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Variable 3-"</span></span><span class="token punctuation">)</span>
<span class="token keyword">var</span> num3 <span class="token operator">=</span> <span class="token class-name">Bool</span><span class="token punctuation">(</span><span class="token function">readLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token operator">!</span><span class="token punctuation">)</span><span class="token operator">!</span>
<span class="token function">print</span><span class="token punctuation">(</span>num3<span class="token punctuation">)</span>
<span class="token keyword">var</span> res1 <span class="token punctuation">:</span> <span class="token class-name">Bool</span>

<span class="token keyword">if</span> <span class="token punctuation">(</span>num1<span class="token punctuation">)</span><span class="token punctuation">{</span>
   res1 <span class="token operator">=</span> num2 <span class="token operator">||</span> num3
<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
   res1 <span class="token operator">=</span> num2 <span class="token operator">&&</span> num3
<span class="token punctuation">}</span>

<span class="token keyword">if</span> <span class="token punctuation">(</span>res1<span class="token punctuation">)</span> <span class="token punctuation">{</span>
   <span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Two of the three variables are true"</span></span><span class="token punctuation">)</span>
<span class="token punctuation">}</span> <span class="token keyword">else</span> <span class="token punctuation">{</span>
   <span class="token function">print</span><span class="token punctuation">(</span><span class="token string-literal"><span class="token string">"Two of the three variables are not true"</span></span><span class="token punctuation">)</span>
<span class="token punctuation">}</span>
</div>

STDIN Input

<span class="typ">Enter</span><span class="pln"> the </span><span class="kwd">value</span><span class="pln"> </span><span class="kwd">of</span><span class="pln"> variables either </span><span class="kwd">true</span><span class="pln"> </span><span class="kwd">or</span><span class="pln"> </span><span class="kwd">false</span><span class="pln">
</span><span class="typ">Variable</span><span class="pln"> </span><span class="lit">1</span><span class="pun">-</span><span class="pln">
</span><span class="kwd">true</span><span class="pln">
</span><span class="typ">Variable</span><span class="pln"> </span><span class="lit">2</span><span class="pun">-</span><span class="pln">
</span><span class="kwd">false</span><span class="pln">
</span><span class="typ">Variable</span><span class="pln"> </span><span class="lit">3</span><span class="pun">-</span><span class="pln">
</span><span class="kwd">true</span>

Output

Two of the three variables are true

Here in the above code, we take the value of three variables from the user with the help readLine() function. readLine() function takes values in string so we use Bool() function to convert the input value in boolean type. Now we compare the variables with each other to find out if the two of the variables are true or not. So the output is "Two of the three variables are true".