لإجراء أي عمليات إدخال وإخراج في لغة C++، نحتاج إلى استخدام ملفات رأس iostream. بدون ملف رأس، لا يمكننا أخذ مدخلات من المستخدم أو طباعة أي مخرجات.
بناء جملة ملف الرأس:
#include #include 'iostream.h'
هناك نوعان من التدفقات في ملف رأس iostream
1. تيار الإدخال : لأخذ أي مدخلات من المستخدم، نحتاج إلى استخدام cin، الذي ينتمي إلى دفق الإدخال
بناء الجملة لاستخدام دفق الإدخال:
std::cin>>variable_name
عند تنفيذ cin، سيتوقف المؤشر عند العبارة المحددة حتى يتم إدخال القيمة. سيتم تخزين القيمة المدخلة في متغير.
2. تيار الإخراج : لطباعة المخرجات، نستخدم الوظائف المضمنة في دفق الإخراج cout
بناء جملة cout
std::cout<<variable_name < pre> <p>When cout is executed, the value in the variable will be printed.</p> <h3>Different operations in iostream</h3> <p> <strong>1. Cin</strong> </p> <p>Using cin, we can take input from the user and store the value in the variable. We need to use the cin keyword followed by >> and the variable name.</p> <p> <strong>Syntax:</strong> </p> <pre> std::cin>>variable_name </pre> <p>To use cin, we need to use <strong>#include </strong> as cin belongs to this header file, and without this, an error will occur.</p> <p> <strong>Example code for cin:</strong> </p> <pre> //using header file iostream #include using namespace std; int main() { string name; //cin declaration cin >> name; return 0; } </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c.webp" alt="What is include iostream in C++"> <p> <strong>Explanation:</strong> </p> <p>In the above code, we used cin to take the input, so to use cin, we included header file. When the input is taken, the string input is stored in the name variable.</p> <p> <strong>2. Cout</strong> </p> <p>To print the output, we need to use the cout keyword, which belongs to the iostream header file. To use cout, we need to use the cout keyword followed by << and variable or the statement to print the output.</p> <p>The syntax for using cout:</p> <pre> std::cout<<variable_name < pre> <p> <strong>Example of using cout:</strong> </p> <pre> //to use the cout statement, we need to use the iostream header file #include using namespace std; int main() { //cout statement is used here to print the statement cout << 'Hi from cout statement'; return 0;} </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-2.webp" alt="What is include iostream in C++"> <p> <strong>Explanation</strong> :</p> <p>In the above code, we used a cout statement to print the statement. To use the cout statement, we need to include iostream.h header file. Once the cout is executed, statement or variable value will be printing the output. To print any statement, we need to use double quotes (' '), and to print a variable value; we need to use just the variable name without double quotes(' ')</p> <p> <strong>3. Cerr</strong> </p> <p>Cerr is used to print errors in C++, which is present in the iostream header file. If we need to print any error message in the code if any condition fails, then cerr is very helpful.</p> <p>The syntax for cerr is:</p> <pre> cerr<<variable_name < pre> <p>Example:</p> <pre> #include using namespace std; int main() { int a; cin>>a; if(a%2==0){ cout<<'the number entered in even number'<<endl; } else{ std::cerr << 'enter proper number' '
'; return 0; < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-3.webp" alt="What is include iostream in C++"> <p> <strong>Explanation:</strong> </p> <p>In the above example, we used cin to take the input and check if the given number is even or not. If the given number is not even, we need to print an error that the given number is not an even number. We use the cerr keyword in the iostream header file to print this error.</p> <p> <strong>4. Clog:</strong> </p> <p>The clog is also used to print error messages, but unlike cerr, clog is buffered, which means the error message is stored in a buffer and then will be printed, but cerr is unbuffered and will not store the error message in the buffer. The clog also belongs to the iostream header file. As the clog is buffered, it will not show the error message immediately. The clog is preferred more than cerr when efficiency is more important.</p> <p>The syntax for clog:</p> <pre> clog<<variable_name; < pre> <p> <strong>Example:</strong> </p> <pre> #include using namespace std; int main() { clog << 'This message is stored in the buffer'; return 0; } </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-4.webp" alt="What is include iostream in C++"> <p> <strong>Explanation:</strong> </p> <p>In the above code, we are printing an error. To print this error, we use cerr, which belongs to the iostream header file. Before printing the error, we store the error in a buffer.</p> <p> <strong>Example</strong> : For all the input and output streams</p> <pre> #include using namespace std; int main() { int a; string b; cin>>a; if(a%2==0){ cout<<'the number entered is even enter a name'<>b; cout< <b; } else{ std::cerr << 'enter even number' '
'; < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-5.webp" alt="What is include iostream in C++"> <p> <strong>Explanation</strong> : In the above code, we used all the input and output streams in the iostream.h header file.</p> <hr></b;></'the></pre></variable_name;></pre></'the></pre></variable_name></pre></variable_name></pre></variable_name> لاستخدام سين، نحن بحاجة إلى استخدام #يشمل لأن cin ينتمي إلى ملف الرأس هذا، وبدون ذلك سيحدث خطأ.
رمز المثال لسين:
//using header file iostream #include using namespace std; int main() { string name; //cin declaration cin >> name; return 0; } انتاج:
توضيح:
في الكود أعلاه، استخدمنا cin لأخذ الإدخال، لذا لاستخدام cin، قمنا بتضمين ملف الرأس. عند أخذ الإدخال، يتم تخزين إدخال السلسلة في متغير الاسم.
2. قطع
لطباعة المخرجات، نحتاج إلى استخدام الكلمة الأساسية cout، التي تنتمي إلى ملف رأس iostream. لاستخدام cout، نحتاج إلى استخدام الكلمة الأساسية cout متبوعة بـ << والمتغير أو العبارة لطباعة المخرجات.
بناء الجملة لاستخدام cout:
std::cout<<variable_name < pre> <p> <strong>Example of using cout:</strong> </p> <pre> //to use the cout statement, we need to use the iostream header file #include using namespace std; int main() { //cout statement is used here to print the statement cout << 'Hi from cout statement'; return 0;} </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-2.webp" alt="What is include iostream in C++"> <p> <strong>Explanation</strong> :</p> <p>In the above code, we used a cout statement to print the statement. To use the cout statement, we need to include iostream.h header file. Once the cout is executed, statement or variable value will be printing the output. To print any statement, we need to use double quotes (' '), and to print a variable value; we need to use just the variable name without double quotes(' ')</p> <p> <strong>3. Cerr</strong> </p> <p>Cerr is used to print errors in C++, which is present in the iostream header file. If we need to print any error message in the code if any condition fails, then cerr is very helpful.</p> <p>The syntax for cerr is:</p> <pre> cerr<<variable_name < pre> <p>Example:</p> <pre> #include using namespace std; int main() { int a; cin>>a; if(a%2==0){ cout<<\'the number entered in even number\'<<endl; } else{ std::cerr << \'enter proper number\' \'
\'; return 0; < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-3.webp" alt="What is include iostream in C++"> <p> <strong>Explanation:</strong> </p> <p>In the above example, we used cin to take the input and check if the given number is even or not. If the given number is not even, we need to print an error that the given number is not an even number. We use the cerr keyword in the iostream header file to print this error.</p> <p> <strong>4. Clog:</strong> </p> <p>The clog is also used to print error messages, but unlike cerr, clog is buffered, which means the error message is stored in a buffer and then will be printed, but cerr is unbuffered and will not store the error message in the buffer. The clog also belongs to the iostream header file. As the clog is buffered, it will not show the error message immediately. The clog is preferred more than cerr when efficiency is more important.</p> <p>The syntax for clog:</p> <pre> clog<<variable_name; < pre> <p> <strong>Example:</strong> </p> <pre> #include using namespace std; int main() { clog << 'This message is stored in the buffer'; return 0; } </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-4.webp" alt="What is include iostream in C++"> <p> <strong>Explanation:</strong> </p> <p>In the above code, we are printing an error. To print this error, we use cerr, which belongs to the iostream header file. Before printing the error, we store the error in a buffer.</p> <p> <strong>Example</strong> : For all the input and output streams</p> <pre> #include using namespace std; int main() { int a; string b; cin>>a; if(a%2==0){ cout<<\'the number entered is even enter a name\'<>b; cout< <b; } else{ std::cerr << \'enter even number\' \'
\'; < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-5.webp" alt="What is include iostream in C++"> <p> <strong>Explanation</strong> : In the above code, we used all the input and output streams in the iostream.h header file.</p> <hr></b;></\'the></pre></variable_name;></pre></\'the></pre></variable_name></pre></variable_name> انتاج:
توضيح :
string.format
في الكود أعلاه، استخدمنا عبارة cout لطباعة البيان. لاستخدام عبارة cout، نحتاج إلى تضمين ملف الرأس iostream.h. بمجرد تنفيذ cout، سيتم طباعة الإخراج أو القيمة المتغيرة. لطباعة أي عبارة، نحتاج إلى استخدام علامات الاقتباس المزدوجة (' ')، وطباعة قيمة متغيرة؛ نحتاج فقط إلى استخدام اسم المتغير بدون علامات الاقتباس المزدوجة (' ')
3. سير
يتم استخدام Cerr لطباعة الأخطاء في C++، الموجودة في ملف رأس iostream. إذا أردنا طباعة أي رسالة خطأ في الكود في حالة فشل أي شرط، فإن cerr مفيد جدًا.
بناء جملة cerr هو:
cerr<<variable_name < pre> <p>Example:</p> <pre> #include using namespace std; int main() { int a; cin>>a; if(a%2==0){ cout<<\'the number entered in even number\'<<endl; } else{ std::cerr << \'enter proper number\' \'
\'; return 0; < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-3.webp" alt="What is include iostream in C++"> <p> <strong>Explanation:</strong> </p> <p>In the above example, we used cin to take the input and check if the given number is even or not. If the given number is not even, we need to print an error that the given number is not an even number. We use the cerr keyword in the iostream header file to print this error.</p> <p> <strong>4. Clog:</strong> </p> <p>The clog is also used to print error messages, but unlike cerr, clog is buffered, which means the error message is stored in a buffer and then will be printed, but cerr is unbuffered and will not store the error message in the buffer. The clog also belongs to the iostream header file. As the clog is buffered, it will not show the error message immediately. The clog is preferred more than cerr when efficiency is more important.</p> <p>The syntax for clog:</p> <pre> clog<<variable_name; < pre> <p> <strong>Example:</strong> </p> <pre> #include using namespace std; int main() { clog << 'This message is stored in the buffer'; return 0; } </pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-4.webp" alt="What is include iostream in C++"> <p> <strong>Explanation:</strong> </p> <p>In the above code, we are printing an error. To print this error, we use cerr, which belongs to the iostream header file. Before printing the error, we store the error in a buffer.</p> <p> <strong>Example</strong> : For all the input and output streams</p> <pre> #include using namespace std; int main() { int a; string b; cin>>a; if(a%2==0){ cout<<\'the number entered is even enter a name\'<>b; cout< <b; } else{ std::cerr << \'enter even number\' \'
\'; < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-5.webp" alt="What is include iostream in C++"> <p> <strong>Explanation</strong> : In the above code, we used all the input and output streams in the iostream.h header file.</p> <hr></b;></\'the></pre></variable_name;></pre></\'the></pre></variable_name> انتاج:
توضيح:
في الكود أعلاه، نقوم بطباعة خطأ. لطباعة هذا الخطأ، نستخدم cerr، الذي ينتمي إلى ملف رأس iostream. قبل طباعة الخطأ، نقوم بتخزين الخطأ في المخزن المؤقت.
مثال : لجميع تيارات الإدخال والإخراج
#include using namespace std; int main() { int a; string b; cin>>a; if(a%2==0){ cout<<\\'the number entered is even enter a name\\'<>b; cout< <b; } else{ std::cerr << \\'enter even number\\' \\'
\\'; < pre> <p> <strong>Output:</strong> </p> <img src="//techcodeview.com/img/c-tutorial/23/what-is-include-iostream-c-5.webp" alt="What is include iostream in C++"> <p> <strong>Explanation</strong> : In the above code, we used all the input and output streams in the iostream.h header file.</p> <hr></b;></\\'the>