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    <p>It is called the the conditional operator or alternativly the ternary operator as it a ternary operator (an operator which takes 3 operands (arguments)), and as it's usually the only operator, that does this.</p> <p>It is also know as the inline if (iif), the ternary if or the question-mark-operator.</p> <p>It is actualy a rather useful feature, as they are expressions, rather than statements, and can therefore be used, for instance in <code>constexpr</code> functions, assigments and such.</p> <p>The C++ Syntax is;</p> <pre><code>logical-or-expression ? expression : assignment-expression </code></pre> <p>It's used as;</p> <pre><code>condition ? condition_is_true_expression : condition_is_false_expression </code></pre> <p>That is, if <code>condition</code> evaluates to <code>true</code>, the expression evaluates to <code>condition_is_true_expression</code> otherwise the expression evaluates to <code>condition_is_false_expression</code>. </p> <p>So in your case, <code>result</code> would always be assigned the value <code>1</code>.</p> <p>Note 1; A common mistake that one makes while working with the conditional operator, is to forget that it has a fairly low <a href="http://en.cppreference.com/w/cpp/language/operator_precedence" rel="noreferrer">operator precedence</a>. </p> <p>Note 2; Some functional languages doesn't provide this operator, as they have expression <code>'if...else'</code> constructs, such as OCaml;</p> <pre><code>let value = if b then 1 else 2 </code></pre> <p>Note 3; A funny use case, which is perfectly valid is using the conditional operator, to decide, which of two variable to assign a value to.</p> <pre><code>(condition ? x : y) = 1; </code></pre> <p>Notice the parentheses are necessary, as this is really what you get without them;</p> <pre><code>condition ? x : (y = 1); </code></pre>
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    1. POWhat is the "?" and ":" sequence actually called?
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    1. CONice explenation, very clear +1
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      1. USCode Guru
    2. COactually, it is defined as *logical-or-expression* ? *expression* : *assignment-expression* by the standard, where the *assignment-expression* can be a *conditional-expression*, a *throw-expression* or an assigment (=, *=, += and the like)
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      1. USArne Mertz
    3. CO@ArneMertz; I was clearly reading the wrong BNF, thanks for correcting, I've editted my answer.
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