What is dangling else problem in Python?

The dangling else is a problem in computer programming in which an optional else clause in an if-else statement results in a nested condition being ambiguous. Formally, the problem is with nested if, if there is only one else statement.

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.

What is dangling in Java?

Dangling pointers arise when an object is deleted or deallocated, without modifying the value of the pointer, so that the pointer still points to the memory location of the deallocated memory. There is no way to delete (or “garbage collect” if you so wish) an object which some reference still points to(1).

How is the dangling else ambiguity resolved in C ++?

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.

Does Java have dangling pointers?

In languages like Java, dangling pointers cannot occur because there is no mechanism to explicitly deallocate memory. Rather, the garbage collector may deallocate memory, but only when the object is no longer reachable from any references.

What is fall through in Java?

When the variable being switched on is equal to a case, the statements following that case will execute until a break statement is reached. When a break statement is reached, the switch terminates, and the flow of control jumps to the next line following the switch statement.

Why do we need left factoring?

Left factoring transforms the grammar to make it useful for top-down parsers. In this technique, we make one production for each common prefixes and the rest of the derivation is added by new productions. Now the parser has only one production per prefix which makes it easier to take decisions.

Why do we remove left factoring?

Removing Left Factoring : On seeing the input α we cannot immediately tell which production to choose to expand A. Left factoring is a grammar transformation that is useful for producing grammar suitable for predictive or top-down parsing.

What is derivation tree in TOC?

Derivation tree is a graphical representation for the derivation of the given production rules of the context free grammar (CFG). It is a way to show how the derivation can be done to obtain some string from a given set of production rules. It is also called as the Parse tree.