Search results
Results from the WOW.Com Content Network
The IF-THEN-ELSE is the basis of the McCarthy formalism: its usage replaces both primitive recursion and the mu-operator. The earliest Fortran compilers supported the computed GOTO statement for multi-way branching. Early ALGOL compilers supported a SWITCH data type which contains a list of "designational expressions". A GOTO statement could ...
When testing x2 and y2, if either of them is empty or zero, then the #switch ends with a warning message, rather than calculating the weighted average of the two amounts x, y, with x2 and y2. Each branch acts as a pre-condition, so the whole #switch structure performs as equivalent to if-elseif-elseif-elseif-else , even though an #if-function ...
However, note that performance suffers when there are more than 100 alternatives. Placing common values earlier in the list of cases can cause the function to execute significantly faster. For each case, either side of the equals sign "=" can be a simple string, a call to a parser function (including #expr to evaulate expressions), or a ...
The detailed semantics of "the" ternary operator as well as its syntax differs significantly from language to language. A top level distinction from one language to another is whether the expressions permit side effects (as in most procedural languages) and whether the language provides short-circuit evaluation semantics, whereby only the selected expression is evaluated (most standard ...
A decision list (DL) of length r is of the form: if f 1 then output b 1 else if f 2 then output b 2... else if f r then output b r. where f i is the i th formula and b i is the i th boolean for {}. The last if-then-else is the default case, which means formula f r is always equal to true.
If-then-else flow diagram A nested if–then–else flow diagram. In computer science, conditionals (that is, conditional statements, conditional expressions and conditional constructs) are programming language constructs that perform different computations or actions or return different values depending on the value of a Boolean expression, called a condition.
Here, the list [0..] represents , x^2>3 represents the predicate, and 2*x represents the output expression.. List comprehensions give results in a defined order (unlike the members of sets); and list comprehensions may generate the members of a list in order, rather than produce the entirety of the list thus allowing, for example, the previous Haskell definition of the members of an infinite list.
The dangling else is a problem in programming of parser generators in which an optional else clause in an if–then(–else) statement can make nested conditional statements ambiguous. Formally, the reference context-free grammar of the language is ambiguous , meaning there is more than one correct parse tree .