Download Examples of setw Function and Floating-Point Numbers Manipulation in C++ and more Schemes and Mind Maps Engineering in PDF only on Docsity!
Electrical and Computer Engineering
1 of 52
Formatting Output
- By default, consecutive integer, floating-point, and
string values are output with no spaces between
them.
- Manipulators are used to control the horizontal
spacing of the output. (endl is one we’ve already
seen)
- Manipulators we’ll use now
endl first three defined in iostream
fixed
showpoint
setw last two defined in iomanip
setprecision
Electrical and Computer Engineering
2 of 52
setw
- setw (set width) lets us control how many character positions the next data item should occupy when it is output. (used for numbers and strings, not chars).s).
- The argument to setw is an integer fieldwidth specification, the data item is right-justified within the fieldwidth.
- If you don’t specify enough characters, the minimum number of characters is used anyway.
Electrical and Computer Engineering
3 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans
Electrical and Computer Engineering
4 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank)) cout << setw(4) << ans << setw(5) 33 << num
Electrical and Computer Engineering 5 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”;
Electrical and Computer Engineering 6 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”; cout << setw(2) << ans 33
Electrical and Computer Engineering
7 of 52
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”; cout << setw(2) << ans << setw(4) 337132 << num
Electrical and Computer Engineering
8 of 52
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”; cout << setw(2) << ans << setw(4) 337132Hi << num << setw(2) << “Hi”;
Electrical and Computer Engineering
9 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”; cout << setw(2) << ans << setw(4) 337132Hi << num << setw(2) << “Hi”; cout << setw(6) << ans
Electrical and Computer Engineering
10 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”; cout << setw(2) << ans << setw(4) 337132Hi << num << setw(2) << “Hi”; cout << setw(6) << ans << setw(3) 33 Hi << “Hi”
Electrical and Computer Engineering 11 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”; cout << setw(2) << ans << setw(4) 337132Hi << num << setw(2) << “Hi”; cout << setw(6) << ans << setw(3) 33 Hi << “Hi” << setw(5) << num;
Electrical and Computer Engineering 12 of 52
UAH CPE 112
setw Examples
Statement (ans = 33, num = 7132) Output ( means blank) cout << setw(4) << ans << setw(5) 33 7132 Hi << num << setw(4) << “Hi”; cout << setw(2) << ans << setw(4) 337132Hi << num << setw(2) << “Hi”; cout << setw(6) << ans << setw(3) 33 Hi << num << setw(5) << “Hi”; cout << setw(7) << “Hi” << setw(4) Hi << num; cout << setw(1) << ans 33
Electrical and Computer Engineering
19 of 52
Floating-Point
Output Examples
ValueValue of xof x StatementStatement Output (Output ( mmeans bl ank)eans bl ank)
ValueValue cout << fixed; 310.0 cout << setw(10) << setprecision(2) << x; 310. 310.00 cout << setw(10) << setprecision(5) << x; 310. 310.0 cout << setw(7) << setprecision(5) << x; 310.
Electrical and Computer Engineering
21 of 52
Floating-Point
Output Examples
of xof x StatementStatement Output (Output ( means blank)means blank)
UAH CPE 112
ValueValue cout << fixed; 310.0 cout << setw(10) << setprecision(2) << x; 310. 310.00 cout << setw(10) << setprecision(5) << x; 310. 310.0 cout << setw(7) << setprecision(5) << x; 310. 4.827 cout << setw(6) << setprecision(2) << x; 4. 4.827 cout << setw(6) << setprecision(1) << x; 4.
Electrical and Computer Engineering 23 of 52
Bad Style Example
Electrical and Computer Engineering 24 of 52
UAH CPE 112
Bad Style
Example Continued
const float PRICE = 150000.0; // Selling price less land int main(){ float grossFootage; // Total square footage float livingFootage; // Living area float costPerFoot; // Cost/foot of living area cout << fixed << showpoint; // Set up floating pt. // output format
grossFootage = LENGTH * WIDTH * STORIES;livingFootage = grossFootage - NON_LIVING_SPACE; costPerFoot = PRICE / livingFootage; cout << "Cost per square foot is “ << setw(6) << setprecision(2) << costPerFoot << endl; return 0; }
Electrical and Computer Engineering
of 52
UAH
Good Style Example
// HouseCost // This program computes the cost per square foot of
// the house, the number of stories, the size of the
//************************************************************** #include iostream> include < > // For () and setprecision using std;
float WIDTH = 30.0; const LENGTH = 40.0; // Length of the house const float STORIES = 2.5; // Number of full stories const float NON_LIVING_SPACE = 825.0; // Garage, closets, etc. const float PRICE = 150000.0; // Selling price less land
26
UA H CP E 11 2
Example Continued
mai n() { f loa t ; // Tot al sq u are fo ota ge f loa t ; // Liv ing a r ea c os t Per Foo t;
c o ut << << sho wp o int // Set up fl oa t ing pt.
g r oss Foo tag e = gr oss Foo ta g e NO N_ L IVI NG_ SPA CE; c o stP erF oot = PRI CE / ;
<< " C ost pe r s qua re foo t i s " << (6 ) < < s et p rec isi on cos tP e rFo ot << ; r e tur n 0 ; }
El e ct r ic a l a nd Co m put er En g ine er i ng
of 52
CPE 112
Addi tio na l
- Now, we consider four functions that operate on strings: size, substr
- Th e len gt h an d siz efun ct i on s b o th ret ur n a n un sig ne d i n teg er val ue equ al to th e n u mb e r of c h ar a ct e rs in th e s t rin g. T he sub st r in g
s ubs tri ng is fou nd, i t r e tur ns th e p o si t io n wh er e t h em at c hb egi ns, i f n o t f oun d, it re tur ns as pe c ial nu mb e r.
- T he s ubs tr f unc tio nr et u rns a par tic ul a r subs tri ng of a st r in g. 28
UA H CP E 11 2
a nds ize
I f length looks li ke t hi s: .length()
- len gt h fun cti on req ui r es no ar g um e nt s , bu t y o um us t s t ill us ep ar e nt h es e s. A lso , - ret ur n in g , s ot he cal l
Electrical and Computer Engineering 29 of 52
U AH CP E1 1 2
E xampl e Usi ng
a nd s ize
Exa mpl e:
stri ng fi r st N am e
fu l lN a me ;
f ir s tN a me
c ou t f i rs t Na m e. l en g th ( ) < < ; // Pr i nt s 9
= fir stN ame
< < f u ll N am e e n dl ;
Electrical and Computer Engineering 30 of 52
U AH CP E1 1 2
M ore About s tring
- st ringi s a C++ cl ass, whi ch has dat a types and fun cti on s a s so c iat ed wi t hi t.
- O the r c las ses m a yh av e a l eng th f unc tio n. To g et th e len gt h fun ct i on as s oci at e dw it h st r in g , we us e t h ed ot ope rat or wi t ha .
- stringh as a dat a type associ at ed wi t h it str ing len gt h An o the r c las sc oul d .
- string::size_types pecifies t hes ize_type as s oci at e dw it h str in g.
Electrical and Computer Engineering
37 of 52
Examples Using find
str1 = “Programming and Problem Solving”;
str2 = “gram”;
Function CallFunction Call Value Returned by FunctionValue Returned by Function
str1.find(“and”) 12
str1.find(“Programming”) 0
str2.find(“and”) string::
str1.find(“Pro”) 0
str1.find(“ro” + str2) 1
Electrical and Computer Engineering
38 of 52
E xampl es Usi ngfind
str1 = “Programming and Problem Solving”;
F uF unction Callnction Call Value Returned by Function
str1.find(“and”) 12
str1.find(“Programming”) 0
s tr2.find(“and”) string::
s tr1.find(“ro” + str2) 1
string::npos
El ectrical and Computer Engineering
39 of 52
UAH CPE 112
Examples Using find
str1 = “Programming and Problem Solving”;
str2 = “gram”;
Function CallFunction Call Value Returned by FunctionValue Returned by Function
str1.find(“and”) 12
str1.find(“Programming”) 0
str2.find(“and”) string::npos
str1.find(“Pro”) 0
str1.find(“ro” + str2) 1
str1.find(“Pr” + str2) string::npos
str1.find(‘ ’) 11
Electrical and Computer Engineering
40 of 52
UAH CPE 112
The substr Function
myString.substr(5, 20)
- Substr returns a string, the arguments to it are of type string::size_type.
Electrical and Computer Engineering 41 of 52
UAH CPE 112
Examples Using substr
myString = “Programming and Problem Solving”;
Funct iFunct io n C a lo n C a lll S tri ng Re t urn ed by Fu n cti on
myString.substr(0, 7) “Program”
Electrical and Computer Engineering 42 of 52
UAH CPE 112
Examples Using substr
myString = “Programming and Problem Solving”;
Function CallFunction Call String Returned by FunctionString Returned by Function
myString.substr(0, 7) “Program” myString.substr(7, 8) “ming and”
Electrical and Computer Engineering
43 of 52
Examples Using substr
myString = “Programming and Problem Solving”;
Function CallFunction Call String Returned by FunctionString Returned by Function
myString.substr(0, 7) “Program” myString.substr(7, 8) “ming and” myString.substr(10, 0) “”
Electrical and Computer Engineering
44 of 52
Examples Using substr
myString = “Programming and Problem Solving”;
Function CallFunction Call String Returned by FunctionString Returned by Function
myString.substr(0, 7) “Program” myString.substr(7, 8) “ming and” myString.substr(10, 0) “” myString.substr(24, 40) “Solving”
Electrical and Computer Engineering
45 of 52
UAH CPE 112
Examples Using substr
myString = “Programming and Problem Solving”;
Function CallFunction Call String Returned by FunctionString Returned by Function
myString.substr(0, 7) “Program” myString.substr(7, 8) “ming and” myString.substr(10, 0 “” myString.substr(24, 40) “Solving” myString.substr(40, 24) Error
Electrical and Computer Engineering
46 of 52
UAH CPE 112
StringOps Program
// This program demonstrates several string operations //**************************************************************** #include #include // For string type using namespace std; int main() { string fullName; string name; string::size_type startPos; fullName = "Jonathan Alexander Peterson"; startPos = fullName.find("Peterson"); name = "Mr. " + fullName.substr(startPos, 8); cout << name << endl; return 0; }
Electrical and Computer Engineering 47 of 52
UAH CPE 112
Problem-Solving Case Study
- Problem: You are asked to calculate the total cost of
painting traffic cones in three different colors. The
cone company uses the area painted to estimate the
total cost.
- Output: The surface area of the cone in square feet,
and the costs of painting the cone in the three
different colors, all displayed in floating point form to
three decimal places.
- Discussion: Cones are measured in inches. A typical
cone is 30 inches high and 8 inches in diameter. Red,
blue, and green paint cost 10, 15, and 18 cents per
square foot, respectively. The non-base surface area
of a cone is πr(r^2 + h^2 )1/2, where r is the radius of the
cone and h is its height.
Electrical and Computer Engineering 48 of 52
UAH CPE 112
High-Level Algorithm
Cone Painting Program
Print
Results
Compute Surface Area of the Cone
Convert
Dimensions
to Feet
Define
Constants
Compute Cost for Each Color
