{"id":25194,"date":"2024-03-16T04:30:23","date_gmt":"2024-03-16T04:30:23","guid":{"rendered":"https:\/\/www.silicloud.com\/blog\/how-is-a-global-variable-defined-in-the-c-language\/"},"modified":"2024-03-22T05:35:08","modified_gmt":"2024-03-22T05:35:08","slug":"how-is-a-global-variable-defined-in-the-c-language","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/blog\/how-is-a-global-variable-defined-in-the-c-language\/","title":{"rendered":"How is a global variable defined in the C language?"},"content":{"rendered":"

In the C language, global variables are defined by declaring variables outside of any function, anywhere in the program. These variables can be accessed and used throughout the entire program. The method for defining global variables is as follows:<\/p>\n

    \n
  1. Variables should be declared outside of all functions, usually at the beginning of the file.<\/li>\n
  2. external<\/li>\n
  3. In functions where global variables are needed, you can simply use the variable name without declaring it again.<\/li>\n<\/ol>\n

    Here is an example:<\/p>\n

    #include<\/span> <stdio.h><\/span><\/span>\r\n\r\nint<\/span> globalVariable; \/\/ \u5728\u6240\u6709\u51fd\u6570\u4e4b\u5916\u58f0\u660e\u5168\u5c40\u53d8\u91cf<\/span>\r\n\r\nvoid<\/span> function1<\/span>()<\/span>\r\n{\r\n    globalVariable = 10<\/span>; \/\/ \u5728\u51fd\u6570\u5185\u4f7f\u7528\u5168\u5c40\u53d8\u91cf<\/span>\r\n    printf<\/span>(\"Value of globalVariable in function1: %d\\n\"<\/span>, globalVariable);\r\n}\r\n\r\nvoid<\/span> function2<\/span>()<\/span>\r\n{\r\n    globalVariable += 5<\/span>; \/\/ \u5728\u53e6\u4e00\u4e2a\u51fd\u6570\u5185\u4f7f\u7528\u5168\u5c40\u53d8\u91cf<\/span>\r\n    printf<\/span>(\"Value of globalVariable in function2: %d\\n\"<\/span>, globalVariable);\r\n}\r\n\r\nint<\/span> main<\/span>()<\/span>\r\n{\r\n    function1();\r\n    function2();\r\n    printf<\/span>(\"Value of globalVariable in main: %d\\n\"<\/span>, globalVariable);\r\n    return<\/span> 0<\/span>;\r\n}\r\n<\/code><\/pre>\n
    Output result:<\/p>\n
    Value of globalVariable in function1: 10\r\nValue of globalVariable in function2: 15\r\nValue of globalVariable in main: 15\r\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
    In the C language, global variables are defined by declaring variables outside of any function, anywhere in the program. These variables can be accessed and used throughout the entire program. The method for defining global variables is as follows: Variables should be declared outside of all functions, usually at the beginning of the file. external […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_import_markdown_pro_load_document_selector":0,"_import_markdown_pro_submit_text_textarea":"","footnotes":""},"categories":[1],"tags":[],"class_list":["post-25194","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"\nHow is a global variable defined in the C language? - Blog - Silicon Cloud<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/blog\/how-is-a-global-variable-defined-in-the-c-language\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How is a global variable defined in the C language?\" \/>\n<meta property=\"og:description\" content=\"In the C language, global variables are defined by declaring variables outside of any function, anywhere in the program. 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