Answer:
Implicit type casting means the type casting done by the compiler during compilation of program whereas Explicit type casting means the programmer explicitly type casts the variables. This is the difference implicit and explicit type casting.
Explanation:
Type casting means the conversion of one data type into another data type. There are two types of type casting. They are Implicit type casting and Explicit type casting.
<u>Implicit type casting:</u> The type casting which is done by the compiler during the compilation of a program. This occurs when we assigning smaller data type to larger data type and also both the data type are compatible. Below example clears the above concepts.
Ex: 
In the above example " i " is " int " data type whereas " l " is long data type but as we assigned the value of " i " to " l ". Here " int " and " long " are compatible data types and we assigned smaller data type ( int - i ) to larger data type ( long - l ) implicit type casting occurs.
<u>Explicit type casting:</u> The type casting which is done by the programmer explicitly to convert one data type into other data type. If we want to assign a value of larger data type to smaller data type explicit type casting is required. Below example clears the above concepts.
Ex: 
In the above example " d " is " double " data type whereas " l " is " long " data type. Here we are explicitly type casting to change larger data value ( double - d ) to smaller data value ( long - l ).
Answer:
Option (4) is the correct answer.
Explanation:
In Java programming language ,array collection starts from 0 index location and ends in a size-1 index location. So to access the last elements the user needs to use a[Size-1] statement. so to modify the value of the last location of the array the user needs to use "a[size-1]= element;".
But when the user wants to add some new value to the end of the array list collection then he needs to use the statement--
a.add(element); //where add is a function, element is a value and a is a array list object.
Another option is invalid because--
- Option 1 is not the correct because "a[3]=element;" modify the value of the 3rd element of the array.
- Option 2 gives a compile-time error because add functions bracts are not closed.
- Option 3 gives the error because a[4] gives the location of the 5th element of the array but the above question says that a is defined with 4 elements.
Answer
Technology can help government handle economic emergencies such as crop and resource shortages.
Explanation
The government can address the concerns of food shortages and water scarcity through embracing new technology interventions to increase farm yields and mitigate the impacts of water shortages. Through crop protection methods, weeds and pest can be controlled. Drip irrigation technology applies water directly to the roots of crops to facilitate high crop production. Other technologies to apply can include organic agriculture and integrated soil fertility management.
