Dynamic Type Binding

A variable is bound to a variable when it is assigned a value in an assignment statement.

When the type of a variable is 1($) bound, the name of the variable can be thought of being bound to a type, in the sense that the type and name of a variable are simultaneously bound. However, when a variable’s type is 2($) bound, its name can be thought of as being only temporarily bound to a type. In reality, the names of variables are never bound to types. Names can be bound to variables and variables can be bound to types.

The primary advantage of static binding of variables to types is that it provides more programming flexibility.

A program to process numeric data in a language that uses dynamic type binding can be written as a _________ program, meaning that it is capable of dealing with data of any numeric type.

Before the mid-1990s, the most commonly used programming languages used static type binding, the primary exceptions being some functional languages such as LISP. However, since then there has been a significant shift to languages that use dynamic type binding. In Python, Ruby, JavaScript, and PHP, type binding is dynamic.

It is possible in JavaScript to write two consecutive assignment statements like that

list = [10.2, 3.5];

list = 47;

A variable can be declared to use dynamic type binding by including the _________ reserved word in its declaration,

A variable can be declared to use dynamic type binding by including the _________ reserved word in its declaration,

Unlike the references in Java, which are restricted to referencing 1($) specific type of value, variables in Ruby can reference 2($) object

suppose that in a particular JavaScript program, i and x are currently the names of scalar numeric variables and y is currently the name of an array. Furthermore, suppose that the program needs the assignment statement

i = x;

but because of a keying error, it has the assignment statement

i = y;

In languages that use static type binding such as C, C++ and Fortran, it happens in many cases that that type of the RHS is automatically converted to the type of the LHS of an assignment statement.