{"id":57638,"date":"2019-06-04T18:45:38","date_gmt":"2019-06-04T13:15:38","guid":{"rendered":"https:\/\/data-flair.training\/blogs\/?p=57638"},"modified":"2021-05-14T13:07:01","modified_gmt":"2021-05-14T07:37:01","slug":"strings-in-c-cpp","status":"publish","type":"post","link":"https:\/\/data-flair.training\/blogs\/strings-in-c-cpp\/","title":{"rendered":"Strings in C – C++ [with Examples & Quizzes]"},"content":{"rendered":"

Are you aware of strings in C\/C++?<\/strong> <\/em><\/p>\n

Strings in C and C++ are nothing but an array of characters terminated by the null character ‘\\0’.\u00a0<\/em>Let us acknowledge the significance of strings in C\/C++ by considering a simple problem.<\/p>\n

Suppose you want to store the details of several employees such as their names, address, and qualification. It is pretty obvious that we can\u2019t use any other data type except strings, as these records contain more than one letter. We can perform strings manipulation in C\/C++. This gives birth to even more applications of strings and makes it all the more significant.<\/p>\n

Don’t forget to attempt the quiz on Strings in C and C++ at the end.<\/em><\/p>\n

1. What are Strings in C and C++?<\/h2>\n

In layman language, strings are nothing but a set of characters treated as a single entity.<\/em><\/p>\n

In programming terminology, a string is:<\/p>\n

    \n
  1. A one-dimensional array of characters.<\/li>\n
  2. Enclosed within double quotes.<\/li>\n
  3. Terminated with a null character, i.e. \u2018\\0\u2019 automatically by the C\/C++ compiler.<\/li>\n<\/ol>\n

    2. Declare Strings<\/h2>\n

    Strings are declared in the same way as arrays in C\/C++<\/strong><\/a>, but restricted to the char data type.\u00a0It is important to declare the string before using it. The C\/C++ compiler reserves a specific block of memory for the sequence of characters. At the end of the string, we append the null character.<\/p>\n

    C++ has an upper hand over C as a string in C++ can be implemented in 2 ways:<\/p>\n

      \n
    1. As an array of characters<\/li>\n
    2. Using the predefined data type – \u201cstring\u201d.<\/li>\n<\/ol>\n

      Its basic syntax is in C\/C++<\/strong><\/p>\n

      char string_name [ 30 ]; \/\/ Here 30 blocks of memory is reserved for the string<\/em><\/p>\n

      The basic syntax exclusively available in C++ is:<\/strong><\/p>\n

      \/* A string data type occupies 32 bytes in the computer memory according to a 64-bit compiler *\/<\/p>\n

      string string_name;<\/em><\/p>\n

      In order to perform string manipulations, it is mandatory to use the header file supported by the C\/C++ standard library, namely:<\/p>\n

      #include<string.h><\/strong><\/em><\/p>\n

      Create your own Header Files in C\u00a0<\/a> within Seconds<\/i><\/b><\/p>\n

      3. Initialize Strings<\/h2>\n

      You can initialize Strings in C in different ways:<\/strong><\/p>\n

      Let us consider some examples to demonstrate the various methods to declare a string:<\/p>\n

      char name[ ] = \u201cDataFlair\u201d;<\/pre>\n
      char name[ ] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , \u2018\\0\u2019 };<\/pre>\n
      char name [ 30 ] = \u201dDataFlair\u201d;<\/pre>\n
      char name [ 30 ] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , \u2018\\0\u2019 };<\/pre>\n
      You can initialize a string in C++ in different ways:<\/strong><\/p>\n
      Let us consider some examples to demonstrate the various methods to declare a string:<\/p>\n
      char name[ ] = \u201cDataFlair\u201d;<\/pre>\n
      char name[ ] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , \u2018\\0\u2019 };<\/pre>\n
      char name [ 30 ] = \u201dDataFlair\u201d;<\/pre>\n
      char name [ 30 ] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , \u2018\\0\u2019 };<\/pre>\n
      string name = \u201cDataFlair\u201d;<\/pre>\n
      4. Memory Occupied by Strings in C & C++<\/h2>\n
      We have already discussed that a character occupies 1 byte of memory in\u00a0Data Types in C\/C++<\/a>.\u00a0<\/strong>Similarly, a string, if initialized first, would occupy the memory:<\/p>\n
      (Number of characters in the string) x 1 byte + 1 byte<\/em><\/p>\n
      Key takeaway:<\/strong> 1\u00a0byte is added while calculating the size of the string. It is because the C\/C++ compiler automatically appends the null character, i.e. \u2018\\0\u2019. This null character consumes 1 byte of memory in the system.<\/p>\n
      Let us get back to the above example<\/strong>:<\/p>\n
      char name[ ] = \u201cDataFlair\u201d;<\/pre>\n
      There data given below should be made in the form of a table<\/em><\/p>\n
      name[0] name[1] name[2] name[3] name[4] name[5] name[6] name[7] name[8] name[9]<\/p>\n\n\n\n\n\n\n\n\n\n\n\n<\/colgroup>\n\n\n
      D<\/td>\na<\/td>\nt<\/td>\na<\/td>\nF<\/td>\nl<\/td>\na<\/td>\ni<\/td>\nr<\/td>\n\\0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
      \"Memory<\/a><\/p>\n
      Example of sizeof() operator in C<\/h5>\n
      Here is a program in C that illustrates the amount of memory allocated to strings with the help of sizeof() operator.<\/p>\n
      #include<stdio.h>\r\nint main()\r\n{\r\n\r\nprintf(\"Welcome to DataFlair tutorials!\\n\\n\");\r\n\r\nchar name1[] = \"DataFlair\";\r\nchar name2[] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , '\\0' };\r\nchar name3[30] = \"DataFlair\"; \/\/ 30 bytes is already allocated\r\nchar name4[30] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , '\\0' }; \/\/30 bytes is already allocated\r\nchar name5[] = \"Data Flair\"; \/\/a blank character occupies 1 byte of memory\r\n\r\nprintf(\"Size of %s is: %ld \\n\",name1,sizeof(name1));\r\nprintf(\"Size of %s is: %ld \\n\",name2,sizeof(name2));\r\nprintf(\"Size of %s is: %ld \\n\",name3,sizeof(name3));\r\nprintf(\"Size of %s is: %ld \\n\",name4,sizeof(name4));\r\nprintf(\"Size of %s is: %ld \\n\",name5,sizeof(name5));\r\nreturn 0;\r\n}<\/pre>\n
      Code on Screen<\/strong><\/p>\n
      \"Example<\/a><\/p>\n
      Output<\/strong><\/p>\n
      \"memory<\/a><\/p>\n
      Example of sizeof() operator in C++<\/h5>\n
      Here is a program in C++ that illustrates the amount of memory allocated to strings with the help of sizeof() operator<\/strong>:<\/p>\n
      #include <iostream>\r\nusing namespace std;\r\n\r\nint main()\r\n{\r\n\r\ncout<<\"Welcome to DataFlair tutorials!\"<<endl<<endl;\r\n\r\nchar name1[] = \"DataFlair\";\r\nchar name2[] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , '\\0' };\r\nchar name3[30] = \"DataFlair\"; \/\/ 30 bytes is already allocated\r\nchar name4[30] = {'D' , 'a' , 't' , 'a' , 'F' , 'l' , 'a' , 'i' , 'r' , '\\0' }; \/\/30 bytes is already allocated\r\nchar name5[] = \"Data Flair\"; \/\/a blank character occupies 1 byte of memory\r\nstring name6 = \"DataFlair\";\r\n\r\ncout<<\"Size of \" << name1 << \" is: \"<< sizeof(name1) <<endl;\r\ncout<<\"Size of \" << name2 << \" is: \"<< sizeof(name2) <<endl;\r\ncout<<\"Size of \" << name3 << \" is: \"<< sizeof(name3) <<endl;\r\ncout<<\"Size of \" << name4 << \" is: \"<< sizeof(name4) <<endl;\r\ncout<<\"Size of \" << name5 << \" is: \"<< sizeof(name5) <<endl;\r\ncout<<\"Size of \" << name6 << \" is: \"<< sizeof(name6) <<endl;\r\n\r\nreturn 0;\r\n}<\/pre>\n
      Code-<\/strong><\/p>\n
      \"Example<\/a><\/p>\n
      Output-<\/strong><\/p>\n
      \"Output<\/a><\/p>\n
      5. Read and Display String in C and C++<\/h2>\n
      Example to read and display strings in C<\/h5>\n
      Here is a code in C that illustrates how to take a string as an input from the user and display it:<\/p>\n
      #include <stdio.h>\r\nint main()\r\n{\r\n\r\nprintf(\"Welcome to DataFlair tutorials!\\n\\n\");\r\n\r\nchar name[30];\r\nprintf(\"Enter the string: \");\r\nscanf(\"%s\", name);\r\nprintf(\"The string is %s\\n\", name);\r\nreturn 0; \r\n}<\/pre>\n
      Code on Screen-<\/strong><\/p>\n
      \"Read<\/a><\/p>\n
      Output-<\/strong><\/p>\n
      \"Read<\/a><\/p>\n
      Example to read and display strings in C++<\/h5>\n
      Here is a code in C++ that illustrates how to take a string as an input from the user and display it:<\/p>\n
      #include <iostream>\r\nusing namespace std;\r\n\r\nint main()\r\n{\r\n\r\ncout<<\"Welcome to DataFlair tutorials!\"<<endl;\r\n\r\nstring name;\r\ncout<<\"Enter the string: \";\r\ncin>>name;\r\ncout<<\"The string is \"<< name <<endl;\r\nreturn 0; \r\n}<\/pre>\n
      Code<\/strong><\/p>\n
      \"Example<\/a><\/p>\n
      Output<\/strong><\/p>\n
      \"Output<\/a><\/p>\n
      6. Read and Display a Line using Strings in C – C++<\/h2>\n
      There are 2 important inbuilt functions in C\/C++<\/a><\/strong><\/em> that help you to read and print a line.<\/p>\n
        \n
      1. gets():<\/strong> It is similar to scanf()<\/strong> which helps you take a line as input.<\/li>\n
      2. puts():<\/strong> It is similar to printf()<\/strong> which helps you display a line as output.<\/li>\n<\/ol>\n
        But there is a problem associated with gets() which makes it dangerous to use because of Buffer Overflow as gets() as it is not capable of performing the array bound test. Hence, it is deprecated. To overcome this problem, fgets()<\/strong> is used instead of gets().<\/p>\n
        Example to read and display line using strings in C<\/h5>\n
        Here is a code in C that illustrates how to read and display a line using strings with the help of fgets()<\/strong> and puts() functions<\/strong>:<\/p>\n
        #define STRING_SIZE 30\r\n#include <stdio.h>\r\nint main()\r\n{\r\n\r\nprintf(\"Welcome to DataFlair tutorials!\\n\\n\");\r\n\r\nchar line[STRING_SIZE];\r\nprintf(\"Enter a sentence \");\r\nfgets(line, STRING_SIZE, stdin); \/\/ To read the string\r\nprintf(\"The sentence is: \");\r\nputs(line); \/\/ To display the string\r\nreturn 0;\r\n}<\/pre>\n
        Code on Screen<\/strong><\/p>\n
        \"Read<\/a><\/p>\n
        Output<\/strong><\/p>\n
        \"Read<\/a><\/p>\n
        In C++, there are 5 important inbuilt functions that help you perform input\/output operations:<\/strong><\/p>\n