C printf（）一行上有两个字符串吗？

Question

您好，我想知道是否可以像在c ++中那样一行输出两个字符串

cout << "hi" << " person";

Answer 1

Just as same as cout , printf will put anything that's supplied to it into the output. cout or printf does not add newlines.

printf("hi");
printf(" person");

Output:

hi person

If you are looking to accomplish it with a single statement in C:

printf( "%s%s", "hi", " person");

For both examples, you will have to #include <stdio.h> . (Not necessary for some compilers).

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Some extra notes on cout : Why can we chain cout in C++?

Please note that cout << "hi" << " person"; is just shorthand for:

cout << "hi";
cout << " person";

Expanded this way, it is not much different from my first example with two printf calls.

std::cout is an instance of std::ostream . And (simply put,) std::ostream overloads the << operator such that it can accept a several types and return a std::ostream reference back. So the operator << on std::ostream is (mostly) same as this function:

std::ostream& printThingsToOutput(std::ostream& where, string s);

The code you supplied can be broken like this:

(cout << "hi") << " person";

First, cout << "hi" is executed. It send the string "hi" to the output buffer, and then returns the cout object. Then the rest of the statement becomes:

cout << " person";

(This also returns a std::ostream reference, which is discarded immediately.)

It is because of the fact that overloaded << operator returns the same std::ostream reference that we can chain the operations together in the manner you have done.

Answer 2

• Option 1:

   printf("%s %s", "hi", "person"); 

• Option 2:

   printf("%s", "hi" "person"); // Concatenation is only valid for string literals 

• Option 3: (for string literals only)

   puts("hi" "person"); 

• Option 4:

   #include <string.h> // ............................ char longbuff[1000] = "hi"; strcat(longbuff, "person"); puts(longbuff); 

Answer 3

您要查找的函数称为puts并在<stdio.h>声明。