כדי לבצע פעולות קלט ופלט כלשהן ב-C++, עלינו להשתמש בקבצי כותרת של iostream. ללא קובץ כותרת, לא נוכל לקבל קלט מהמשתמש או להדפיס פלט כלשהו.
תחביר של קובץ כותרת:
#include #include 'iostream.h'
ישנם שני סוגים של זרמים בקובץ הכותרת של iostream
1. קלט זרם : כדי לקחת כל קלט מהמשתמש, עלינו להשתמש ב-cin, השייך לזרם הקלט
תחביר לשימוש בזרם קלט:
java הוסף למערך
std::cin>>variable_name
כאשר ה-cin מבוצע, הסמן ייעצר במשפט המסוים עד להזנת הערך. הערך שהוזן יישמר במשתנה.
2. פלט זרם : כדי להדפיס את הפלט, אנו משתמשים בפונקציות מובנות בזרם הפלט של cout
תחביר עבור 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> כדי להשתמש ב-cin, אנחנו צריכים להשתמש #לִכלוֹל מכיוון ש-cin שייך לקובץ הכותרת הזה, וללא זה, תתרחש שגיאה.
קוד לדוגמה עבור cin:
אורך מערך java
//using header file iostream #include using namespace std; int main() { string name; //cin declaration cin >> name; return 0; } תְפוּקָה:
הֶסבֵּר:
אתרים כמו coomeet
בקוד שלמעלה, השתמשנו ב-cin כדי לקחת את הקלט, אז כדי להשתמש ב-cin, כללנו קובץ כותרת. כאשר הקלט נלקח, קלט המחרוזת מאוחסן במשתנה השם.
2. קאוט
כדי להדפיס את הפלט, עלינו להשתמש במילת המפתח cout, השייכת לקובץ הכותרת של iostream. כדי להשתמש ב-cout, עלינו להשתמש במילת המפתח cout ואחריה << ובמשתנה או במשפט כדי להדפיס את הפלט.
התחביר לשימוש ב-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> תְפוּקָה:
הֶסבֵּר :
בקוד לעיל, השתמשנו בהצהרת cout כדי להדפיס את ההצהרה. כדי להשתמש במשפט cout, עלינו לכלול את קובץ הכותרת iostream.h. לאחר ביצוע ה-cout, ההצהרה או ערך המשתנה ידפיסו את הפלט. כדי להדפיס משפט כלשהו, עלינו להשתמש במירכאות כפולות (' '), ולהדפיס ערך משתנה; עלינו להשתמש רק בשם המשתנה ללא מרכאות כפולות(' ')
אלגוריתמים חיפוש בינארי
3. Cerr
Cerr משמש להדפסת שגיאות ב-C++, הקיים בקובץ הכותרת של iostream. אם אנחנו צריכים להדפיס הודעת שגיאה כלשהי בקוד אם מצב כלשהו נכשל, אז cerr עוזר מאוד.
התחביר עבור cerr הוא:
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> תְפוּקָה:
ירושה ג'אווה
הֶסבֵּר:
בקוד לעיל, אנו מדפיסים שגיאה. כדי להדפיס שגיאה זו, אנו משתמשים ב-cerr, השייך לקובץ הכותרת של iostream. לפני הדפסת השגיאה, אנו מאחסנים את השגיאה במאגר.
דוגמא : עבור כל זרמי הקלט והפלט
#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>