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Conditional operator

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<div class="side-box-text plainlist">Look up <a href="https://en.wiktionary.org/wiki/conditional_operator" class="extiw external" title="wiktionary:conditional operator">conditional operator</a> in Wiktionary, the free dictionary.</div></div>

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The conditional operator is supported in many <a href="Programming_language" title="Programming language">programming languages</a>. This term usually refers to <code>?:</code> as in <a href="C_(programming_language)" title="C (programming language)">C</a>, <a href="C%2B%2B" title="C++">C++</a>, <a href="C_sharp_(programming_language)" class="mw-redirect" title="C sharp (programming language)">C#</a>, <a href="JavaScript" title="JavaScript">JavaScript</a> and <a href="PHP" title="PHP">PHP</a>. However, in Java, this term can also refer to <code>&&</code> and <code>||</code>.

In some programming languages, e.g. Java, the term conditional operator refers to <a href="Short-circuit_evaluation" title="Short-circuit evaluation">short circuit boolean operators</a> <code>&&</code> and <code>||</code>. The second expression is evaluated only when the first expression is not sufficient to determine the value of the whole expression.<a href="#cite_note-1">[1]</a>

<div class="mw-heading mw-heading3"><h3 id="Difference_from_bitwise_operator">Difference from bitwise operator</h3></div>

<code>&</code> and <code>|</code> are <a href="Bitwise_operation" title="Bitwise operation">bitwise operators</a> that occur in many programming languages. The major difference is that bitwise operations operate on the individual bits of a binary numeral, whereas conditional operators operate on logical operations. Additionally, expressions before and after a bitwise operator are always evaluated.

<div class="mw-highlight mw-highlight-lang-java mw-content-ltr" dir="ltr"><pre>if (expression1 || expression2 || expression3)

</pre></div>If expression 1 is true, expressions 2 and 3 are NOT checked.

<div class="mw-highlight mw-highlight-lang-java mw-content-ltr" dir="ltr"><pre>if (expression1 | expression2 | expression3)

</pre></div>This checks expressions 2 and 3, even if expression 1 is true.

Short circuit operators can reduce run times by avoiding unnecessary calculations. They can also avoid Null Exceptions when expression 1 checks whether an object is valid.

<div class="mw-heading mw-heading3"><h3 id="Usage_in_Java">Usage in Java</h3></div>

<div class="mw-highlight mw-highlight-lang-java mw-content-ltr" dir="ltr"><pre>class ConditionalDemo1 {

public static void main(String[] args) {

int value1 = 1;

int value2 = 2;

if ((value1 == 1) && (value2 == 2))

System.out.println("value1 is 1 AND value2 is 2");

if ((value1 == 1) || (value2 == 1))

}

}

</pre></div>

In some programming languages, <a href="%3F%3A" class="mw-redirect" title="?:">?:</a> is called the conditional operator. It is a type of <a href="Ternary_operator" class="mw-redirect" title="Ternary operator">ternary operator</a>. However, ternary operator in most situations refers specifically to <a href="%3F%3A" class="mw-redirect" title="?:">?:</a> because it is the only operator that takes three operands.<a href="#cite_note-:0-2">[2]</a>

<div class="mw-heading mw-heading3"><h3 id="Regular_usage_of_"?:"">Regular usage of "?:"</h3></div>

<code>?:</code> is used in conditional expressions. Programmers can rewrite an if-then-else expression in a more concise way by using the conditional operator.<a href="#cite_note-3">[3]</a>

<div class="mw-heading mw-heading4"><h4 id="Syntax">Syntax</h4></div>

<div class="mw-highlight mw-highlight-lang-java mw-content-ltr" dir="ltr"><pre>condition ? expression 1 : expression 2

</pre></div>condition: An expression which is evaluated as a <a href="Boolean_algebra" title="Boolean algebra">boolean</a> value.

expression 1, expression 2: Expressions with values of any type.

If the condition is evaluated to true, the expression 1 will be evaluated. If the condition is evaluated to false, the expression 2 will be evaluated.

It should be read as: "If condition is true, assign the value of expression 1 to result. Otherwise, assign the value of expression 2 to result."

<div class="mw-heading mw-heading4"><h4 id="Association_property">Association property</h4></div>

The conditional operator is right-associative, meaning that operations are grouped from right to left. For example, an expression of the form a ? b : c ? d : e is evaluated as a ? b : (c ? d : e).<a href="#cite_note-:0-2">[2]</a> The exception is <a href="PHP" title="PHP">PHP</a>, in which it was left-associative prior to version 8, and is non-associative thereafter.<a href="#cite_note-4">[4]</a>

<div class="mw-heading mw-heading4"><h4 id="Examples_by_languages">Examples by languages</h4></div>

<div class="mw-highlight mw-highlight-lang-java mw-content-ltr" dir="ltr"><pre>class ConditionalDemo2 {

int result;

boolean someCondition = true;

result = someCondition ? value1 : value2;

}

}

</pre></div>In this example, because someCondition is true, this program prints "1" to the screen. Use the ?: operator instead of an if-then-else statement if it makes your code more readable; for example, when the expressions are compact and without side-effects (such as assignments).

<div class="mw-highlight mw-highlight-lang-c++ mw-content-ltr" dir="ltr"><pre>#include <iostream>

int main() {

int x = 1;

int y = 2;

std::cout << ( x > y ? x : y ) << " is the greater of the two." << std::endl;

}

</pre></div>There are several rules that apply to the second and third operands in C++:

<ul><li>If both operands are of the same type, the result is of that type</li>

<li>If both operands are of arithmetic or enumeration types, the usual arithmetic conversions (covered in Standard Conversions) are performed to convert them to a common type</li>

<li>If both operands are of pointer types or if one is a pointer type and the other is a constant expression that evaluates to 0, pointer conversions are performed to convert them to a common type</li>

<li>If both operands are of reference types, reference conversions are performed to convert them to a common type</li>

<li>If both operands are of type void, the common type is type void</li>

<li>If both operands are of the same user-defined type, the common type is that type.<a href="#cite_note-:1-5">[5]</a></li></ul>

<div class="mw-highlight mw-highlight-lang-csharp mw-content-ltr" dir="ltr"><pre>// condition ? first_expression : second_expression;

static double sinc(double x)

{

return x != 0.0 ? Math.Sin(x) / x : 1.0;

}

</pre></div>

There are several rules that apply to the second and third operands x and y in C#:

<li>If an implicit conversion exists from X to Y but not from Y to X, Y is the type of the conditional expression.</li>

<li>If an implicit conversion exists from Y to X but not from X to Y, X is the type of the conditional expression.</li>

<li>Otherwise, no expression type can be determined, and a compile-time error occurs.</li>

<li>If only one of x and y has a type, and both x and y are implicitly convertible to that type, that type is the type of the conditional expression.</li>

<li>Otherwise, no expression type can be determined, and a compile-time error occurs.<a href="#cite_note-:0-2">[2]</a></li></ul>

<div class="mw-heading mw-heading5"><h5 id="JavaScript">JavaScript</h5></div>

<div class="mw-highlight mw-highlight-lang-javascript mw-content-ltr" dir="ltr"><pre>var age = 26;

var beverage = (age >= 21) ? "Beer" : "Juice";

console.log(beverage); // "Beer"

</pre></div>

The conditional operator of JavaScript is compatible with the following browsers:

<a href="Google_Chrome" title="Google Chrome">Chrome</a>, <a href="Microsoft_Edge" title="Microsoft Edge">Edge</a>, <a href="Firefox" title="Firefox">Firefox</a> (1), <a href="Internet_Explorer" title="Internet Explorer">Internet Explorer</a>, <a href="Opera_(web_browser)" title="Opera (web browser)">Opera</a>, <a href="Safari_(web_browser)" title="Safari (web browser)">Safari</a>, Android webview, <a href="Google_Chrome_for_Android" class="mw-redirect" title="Google Chrome for Android">Chrome for Android</a>, <a href="Microsoft_Edge" title="Microsoft Edge">Edge Mobile</a>, <a href="Firefox_for_Android" title="Firefox for Android">Firefox for Android</a> (4), Opera for Android, Safari on IOS, <a href="Samsung_Internet" title="Samsung Internet">Samsung Internet</a>, <a href="Node.js" title="Node.js">Node.js</a>.<a href="#cite_note-6">[6]</a>

<div class="mw-heading mw-heading3"><h3 id="Special_usage_in_conditional_chain">Special usage in conditional chain</h3></div>

The ternary operator is right-associative, which means it can be "chained" in the following way, similar to an if ... else if ... else if ... else chain.<a href="#cite_note-:1-5">[5]</a>

<div class="mw-heading mw-heading4"><h4 id="Examples_by_languages_2">Examples by languages</h4></div>

<div class="mw-heading mw-heading5"><h5 id="JavaScript_2">JavaScript</h5></div>

<div class="mw-highlight mw-highlight-lang-javascript mw-content-ltr" dir="ltr"><pre>function example(…) {

return condition1 ? value1

: condition2 ? value2

: condition3 ? value3

: value4;

}

// Equivalent to:

function example(…) {

if (condition1) { return value1; }

else if (condition2) { return value2; }

else if (condition3) { return value3; }

else { return value4; }

}

</pre></div>

<div class="mw-highlight mw-highlight-lang-c++ mw-content-ltr" dir="ltr"><pre>const double a =

expression1 ? a1

: expression2 ? a2

: expression3 ? a3

: /*otherwise*/ a4;

// Equivalent to:

double a;

if (expression1)

a = a1;

a = a2;

a = a3;

else /*otherwise*/

a = a4;

</pre></div>

<div class="mw-heading mw-heading3"><h3 id="Special_usage_in_assignment_expression">Special usage in assignment expression</h3></div>

the conditional operator can yield a <a href="Value_(computer_science)#lrvalue" title="Value (computer science)">L-value</a> in C/C++ which can be assigned another value, but the vast majority of programmers consider this extremely poor style, if only because of the technique's obscurity.<a href="#cite_note-7">[7]</a>

<div class="mw-highlight mw-highlight-lang-cpp mw-content-ltr" dir="ltr"><pre>((foo) ? bar : baz) = frink;

// equivalent to:

if (foo)

bar = frink;

else

baz = frink;

</pre></div>

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</style><a href="%3F%3A" class="mw-redirect" title="?:">?:</a>, a conditional operator in computer programming</li>

<li><a href="Ternary_operation" title="Ternary operation">Ternary operation</a></li>

<li><a href="Bitwise_operation" title="Bitwise operation">Bitwise operators</a></li>

<li><a href="Short-circuit_evaluation" title="Short-circuit evaluation">Short-circuit boolean operators</a></li>

<li><a href="Operator_(programming)" class="mw-redirect" title="Operator (programming)">Operator (programming)</a></li></ul>

<div class="mw-heading mw-heading2"><h2 id="References">References</h2></div>

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</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://docs.oracle.com/javase/tutorial/java/nutsandbolts/op2.html">"Equality, Relational, and Conditional Operators (The Java™ Tutorials > Learning the Java Language > Language Basics)"</a>. docs.oracle.com. Retrieved 2019-04-29.</cite>

</li>

<li id="cite_note-:0-2">^ <a href="#cite_ref-:0_2-0">a</a> <a href="#cite_ref-:0_2-1">b</a> <a href="#cite_ref-:0_2-2">c</a> <cite id="CITEREFBillWagner" class="citation web cs1">BillWagner. <a rel="nofollow" class="external text" href="https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/conditional-operator">"?: Operator - C# Reference"</a>. docs.microsoft.com. Retrieved 2019-04-29.</cite>

</li>

<li id="cite_note-3"><a href="#cite_ref-3">^</a> <cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.cafeaulait.org/course/week2/43.html">"The ? : operator in Java"</a>. www.cafeaulait.org. Retrieved 2019-04-29.</cite>

</li>

<li id="cite_note-4"><a href="#cite_ref-4">^</a> <a rel="nofollow" class="external free" href="https://www.php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary">https://www.php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary</a>

</li>

<li id="cite_note-:1-5">^ <a href="#cite_ref-:1_5-0">a</a> <a href="#cite_ref-:1_5-1">b</a> <cite id="CITEREFmikeblome" class="citation web cs1">mikeblome. <a rel="nofollow" class="external text" href="https://docs.microsoft.com/en-us/cpp/cpp/conditional-operator-q">"Conditional Operator: ?"</a>. docs.microsoft.com. Retrieved 2019-04-29.</cite>

</li>

<li id="cite_note-6"><a href="#cite_ref-6">^</a> <cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Conditional_Operator">"Conditional (ternary) operator - JavaScript"</a>. developer.mozilla.org. Retrieved 2019-04-29.</cite>

</li>

<li id="cite_note-7"><a href="#cite_ref-7">^</a> <cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://wiki.c2.com/?ConditionalOperator">"Conditional Operator"</a>. wiki.c2.com. Retrieved 2019-04-29.</cite>

</li>

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