2.12: Variable Assignment and Initalization

there are two alternative techniques for initializing variables.

The first is to enclose the initialization value in a set of parentheses, just after the variable name. Here is how you would define the value variable and initialize it to 5 using this technique: int value(5); The second alternative, introduced in C++ 11, is to enclose the initialization value in a set of curly braces, just after the variable name. Here is how you would define the value variable and initialize it to 5 using the brace notation: int value {5}; // This only works with C++ 11 or higher.

The ____________word is intended to simplify the syntax of declarations that are more complex than the ones .

auto key

Declare a numerical variable precise and initialize it to the value 1.09388641.

double precise=1.09388641;

Given two double variables , bestValue and secondBestValue, write some code that swaps their values . Declare any additional variables as necessary.

double tempValue; tempValue=bestValue; bestValue=secondBestValue; secondBestValue=tempValue;

Given an integer variable drivingAge that has already been declared , write a statement that assigns the value 17 to drivingAge.

drivingAge=17;

Declare a variable temperature and initialize it to 98.6.

float temperature=98.6;

Given two integer variables num and highest, write a statement that gives highest the same value that num has.

highest = num;

When a value is assigned to a variable as part of the variable's definition, it is called an ___________

initialization

Declare an integer variable cardsInHand and initialize it to 13.

int cardsInHand=13;

Declare and initialize the following variables : A variable monthOfYear, initialized to the value 11 A variable companyRevenue, initialized to the value 5666777 A variable firstClassTicketPrice, initialized to the value 6000 A variable totalPopulation, initialized to the value 1222333

int monthOfYear=11; long companyRevenue=5666777; int firstClassTicketPrice=6000; long totalPopulation=1222333;

Write a statement that declares an int variable presidentialTerm and initializes it to 4.

int presidentialTerm=4;

Given three already declared int variables , i, j, and temp, write some code that swaps the values in i and j. Use temp to hold the value of i and then assign j's value to i. The original value of i, which was saved in temp, can now be assigned to j.

temp=i; i=j; j=temp;

It checks to make sure the value you are initializing the variable with matches the data type of the variable. For example, assume that doubleVal is a double variable with 6.2 stored in it. Using the assignment operator, it is possible to write either of the following statements: int value1 = 4.9; // This will store 4 in value1 int value2 = doubleVal; // This will store 6 in value2

the brace notation offers what advantage?

Declare a string variable named str and initialize it to Hello.

string str="Hello";

Given two int variables , firstPlaceWinner and secondPlaceWinner, write some code that swaps their values . Declare any additional variables as necessary, but do not redeclare firstPlaceWinner and secondPlaceWinner.

int temp; temp=firstPlaceWinner; firstPlaceWinner=secondPlaceWinner; secondPlaceWinner=temp;

The most common way to initialize a variable is to use the assignment operator in the variable definition statement.

int value = 5;

Write a declaration of an int variable year and initialize it to 365.

int year=365;

Given two int variables , i and j, which have been declared and initialized , and two other int variables , itemp and jtemp, which have been declared , write some code that swaps the values in i and j by copying their values to itemp and jtemp, respectively, and then copying itemp and jtemp to j and i, respectively.

itemp=i; jtemp=j; i=jtemp; j=itemp;

In C++ terminology, the operand on the left side of the = symbol must be an __________

lvalue.

Write a statement to set the value of num to 4 (num is a variable that has already been declared ).

num=4;

The operand on the right side of the = symbol must be an_________

rvalue.

The ___________of a variable is the part of the program where the variable may be used.

scope