How is the dangling else ambiguity resolved in Java?

How is the dangling else ambiguity resolved in Java?

Java, C and C++ have chosen to resolve the Dangling-Else ambiguity uses the following rule: An else keyword always associates with the nearest preceeding if keyword that does NOT cause a syntax error.

Which of the following is used to correct a dangling else?

Dangling else is a problem occurs when we use nested if. Statement; this is called dangling else problem. To overcome this we use braces and follow indentation.

Which of the following statements creates the dangling else problem?

The dangling else problem is often caused when there is an if statement without the presence of a true or a false statement. A switch statement without a default does not cause the dangling else problem. This problem mainly arises due to nested if statements.

How do you remove ambiguity from a grammar?

Methods To Remove Ambiguity-

1. By fixing the grammar.
2. By adding grouping rules.
3. By using semantics and choosing the parse that makes the most sense.
4. By adding the precedence rules or other context sensitive parsing rules.

What is dangling else ambiguity examples?

The dangling else is a problem in computer programming in which an optional else clause in an if–then(–else) statement results in nested conditionals being ambiguous. Formally, the reference context-free grammar of the language is ambiguous, meaning there is more than one correct parse tree.

Does left factoring remove ambiguity?

2 Answers. In the case of the dangling else, ambiguity is not eliminated by left factoring. You will still have two parse trees for nested if statements. This is exactly what left factoring usually refers to.

What is ambiguity how it is removed explain with example?

A grammar is said to be ambiguous if there exists more than one leftmost derivation or more than one rightmost derivation or more than one parse tree for the given input string. No method can automatically detect and remove the ambiguity, but we can remove ambiguity by re-writing the whole grammar without ambiguity.

What do you mean by ambiguity in grammar write an example?

A grammar is said to be ambiguous if there exists more than one left most derivation or more than one right most derivation or more than one parse tree for a given input string. If the grammar is not ambiguous then we call it unambiguous grammar.

What is dangling else with example?

What is the problem of dangling else when does it arise?

When the number of if statement is more or less then that of else statement confusion arises in matching by the compiler.. the problem so called is dangling else . It can be overcome by the use of braces.

Why do we remove left factoring?

Here is a simple way to differentiate between both terms: Furthermore, If a Grammar is Left Recursive, it might result into infinite loop hence we need to Eliminate Left Recursion. If a Grammar is Left Factoring, it confuses the parser hence we need to Remove Left Factoring as well.

How do I remove left recursion& Left factoring from grammar?

Elimination of Left Recursion Left recursion is eliminated by converting the grammar into a right recursive grammar.

How to resolve dangling-else ambiguity in a language?

Resolving the Dangling-Else ambiguity There are a number of techniques to resolve ambiguity in a language: The elegant way is to design languages that are NOT ambiguous The simple-minded way is to design rules to resolve ambiguity

When to use dangling else in a language?

The dangling else ambiguity. (The latter method is used when the resolve an ambiguity when an ambiguity is discovered after a language has been designed and in use ) How to design languages that avoid the dangling-else ambiguity A slightly more complex syntax rule is used for the conditional…

What is the problem with the dangling else problem?

A useful explanation of the dangling else problem can be found at Dangling Else, Yet Again The problem is one of apparent ambiguity. I say apparent ambiguity because the compiler knows exactly how it will interpret a dangling else, but humans often do not.

When does dangling else occur in nested if?

Dangling else is a problem occurs when we use nested if. Here in the above example we actually want to give the else clause to the outer most if condition but it is considered for the innermost if condition .this is called dangling else problem. To overcome this we use braces and follow indentation.