The computer is a machine that calculates.
However, the character string cannot be used for the character string to calculate because it doesn't pass to the last.
It is necessary to treat as a numerical value when calculating.
Naturally, if it is a numerical value, it is possible to use it to calculate.

[ Or more   value and figure   ]
Though it might be a word of the meaning as which the numerical value and the figure are the same in daily life
It is distinguished clearly in the world of computer.
The numerical value can be used to calculate by the one to express the number.
The figure (For the convenience of man) doesn't pass ..the same externals as the numerical value it...
It is not possible to use it not the one it for the computer to express the number but to calculate.

Recall the program made in the preceding chapter.

 
#include <stdio.h> 

int main(void)  
{
	printf("Hello, world\n");  
	return 0;
}

The character string enclosed with ""might be especially called a string literal in this manner.

[   Character row literal   ]
Hollerith constant enclosed with ""of burial while programming it.

1234 is a numerical value.
"1234" is a figure. (character string)

Use an output conversion finger fixed child to display the numerical value by the printf function.
This is a kind of the sign that buries in the character string and is used.

[   Output conversion finger fixed child   ]
When it wants to convert outside data into character string and display
Sign that specifies the conversion regime.

Anyway, [sukara] and the usage are seen in to see is to believe.
The following program is a numerical value It is program that displays 100.

 
#include <stdio.h> 

int main(void)  
{
	printf("%d",100);  
	return 0;
}

100

It explained the method of displaying the numerical value by handling %d finger fixed child to the printf function in the preceding clause.
However, what on earth you mean becomes cramped only by the numerical value.
To the unit It is various 100 yen, 100 people, and 100Kg and 100 times, etc. even if it is said 100.

Solve it if the numerical value and the character string are combined and displayed to solve this problem.
The following program is an example of combining the numerical value and the character string and displaying 100 yen.

 
#include <stdio.h> 

int main(void) 
{
	printf("%d",100); 
	Printf ("Yen \n");
	return 0; 
}

[ Treatment of this word during   day   ]
C language can display not only the one-byte character but also the em-size character.
However, to assume the one-byte character to be a basis
There is troublesome point a lot when the em-size character is used in full scale.
There is no problem only if it displays it.
(The problem might happen in the compiler made of foreign countries. )

100 yen

%d finger fixed child can use it by combining with other character strings.
When %d finger fixed child is handled to the character string, the part is replaced by the numerical value.
The following program is an example of displaying 100 yen by one time of the printf function.

 
#include <stdio.h> 

int main(void) 
{
	Printf ("%d yen \n"  100);
	return 0; 
}

100 yen

In the preceding clause, it explained the method of burying %d finger fixed child in the character string.
Let's challenge the display of an easy expression by using this method.
The expression It is a very easy expression called 100+200=300.
Of course, do not calculate yet though it displays by using the numerical value.

If %d finger fixed child is handled, these kind of things are not the winds either.
The following program is an example of displaying 100+200=300.

 
#include <stdio.h> 

int main(void)  
{
	printf("%d+",100);  
	printf("%d=",200);  
	printf("%d\n",300);  
	return 0;
}

100+200=300

Actually, there is no problem no matter how %d finger fixed child uses it in one character string.
Specify three numerical values when you handle three %d finger fixed children.
The following program is an example of handling and displaying three %d finger fixed children.

 
#include <stdio.h> 

int main(void)  
{
	printf("%d+%d=%d\n",100,200,300);  
	return 0;
}

100+200=300