C++ Output Formatting
Formatting output plays an important role and it makes the output easy to read and understand. C++ provides several input / output manipulators. There are two types of I / O manipulators: setw() and setprecision(). To use these manipulations, you must include the header file iomanip.h
#include < iomanip.h >
C++ Setw() Manipulator
The setw() manipulator set the width of the specified area for the output.It takes the size of the field as a parameter.For example, the code :
cout<< setw(6) << "P";
Output :- _ _ _ _ _ P
cout<< setw(8) << 22;
Output :- _ _ _ _ _ _ 2 2
cout<< setw(8) << 4444;
Output :- _ _ _ _ 4 4 4 4
cout<< setw(8) << 666666;
Output :- _ _ 6 6 6 6 6 6
C++ Setprecision() Manipulator
Setprecision() Manipulators sets the total number of digits to be displayed when the manipulator floating point number is printed.
cout<< Setprecision(5) << 123.456;
Output :- 123.46 \\It will print the output to the screen(Notice the rounding)
cout<< Setprecision(2) << 1.1658;
Output :- 1.2
cout<< Setprecision(4) << 125.721;
Output :- 125.7
cout<< Setprecision(6) << 125.6987;
Output :- 125.699
Precedence of Operators
The associativity of an operator is a property that determines how operators of the same precedence are grouped in the absence of parentheses.
For example A = 3 + 5 * 3; here, A is assigned 18, not 24 because operator * has higher precedence than +, so it first gets multiplied with 5*3 and then adds into 3.
Operators are listed top to bottom, in descending precedence.
Following table lists the precedence order of operators:
| Category | Operator | Associativity |
|---|---|---|
| Postfix | () [] -> . ++ - - | Left to right |
| Unary | + - ! ~ ++ - - (type)* & sizeof | Right to left |
| Multiplicative | * / % | Left to right |
| Additive | + - | Left to right |
| Shift | << >> | Left to right |
| Relational | < <= > >= | Left to right |
| Equality | == != | Left to right |
| Bitwise AND | & | Left to right |
| Bitwise XOR | ^ | Left to right |
| Bitwise OR | | | Left to right |
| Logical AND | && | Left to right |
| Logical OR | || | Left to right |
| Conditional | ?: | Right to left |
| Assignment | = += -= *= /= %=>>= <<= &= ^= |= | Right to left |
| Comma | , | Left to right |
Exercise:-
1. Which operator has the highest Precedence?
View Answer
2. Which operator has the lowest Precedence?
View Answer
Program :-
C++ Program to Find LCM
#include <iostream>
using namespace std;
int main()
{
int n1, n2, max;
cout << "Enter two numbers: ";
cin >> n1 >> n2;
// maximum value between n1 and n2 is stored in max
max = (n1 > n2) ? n1 : n2;
do
{
if (max % n1 == 0 && max % n2 == 0)
{
cout << "LCM = " << max;
break;
}
else
++max;
} while (true);
return 0;
}
Output :
Enter two numbers: 12 18 LCM = 36
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