Consider the example: Suppose we wish to store information about an employee-id, name, and type. A union variable can be assigned to another union variable.
The address of the union variable can be obtained using the address-of operator. A function can accept and return a union or a pointer to a union. Instances can then be created using this synonym. So in this lesson, we have learned about the Structures and unions in C. Now, in the next lesson, we will learn about file handling in C.
Structures and Unions in C Table of Contents. Related Posts. June 9th, 0 Comments. June 6th, 0 Comments. Go to Top. Each member of a structure is allocated separate memory space. Structure variable occupies the sum of sizes of all members in the variables. The amount of memory required is the same as its largest number. Only the first member of the union can be initialized.
The union statement defines a new data type with more than one member for your program. The union tag is optional and each member definition is a normal variable definition, such as int i; or float f; or any other valid variable definition.
At the end of the union's definition, before the final semicolon, you can specify one or more union variables but it is optional. Now, a variable of Data type can store an integer, a floating-point number, or a string of characters. It means a single variable, i. Mizoram Current Affairs. Nagaland Current Affairs. Odisha Current Affairs. Puducherry Current Affairs. Punjab Current Affairs. Rajasthan Current Affairs. Sikkim Current Affairs. Tamil Nadu Current Affairs. Telangana Current Affairs.
Tripura Current Affairs. Uttarakhand Current Affairs. Uttar Pradesh Current Affairs. West Bengal Current Affairs. November October September August July June May April Agriculture Current Affairs. Bank Current Affairs. Committees and Commissions Current Affairs. A Unions creates a storage location that can be used by any of the Union members but only one at a time.
Also, when a different Union member is assigned a new value, it supersedes the value of the previous member. Unions can be initialized when the variable is declared. But it can be initialized only with a value of the same type as the first Union member , unlike the initialization in a Structure. Here, the initialization of the Union variable is invalid because the value is not the same as the type of the first member i. Object of a Structure will get memory equal to the sum of memory of all the members.
Any changes made in one member will reflect in other members too. What are Structures in C? Structures help create any complex data items in a much meaningful and organized way. It is often used in creating a complex program that provides an analogous concept of maintaining a record.
When we declare a Structure , it forms a template that is used to create Structure objects i. The variables inside the Structure are called members also called elements or fields. How to define a Structure in C? These data fields are called Structure elements or members.
Each member maybe belongs to a different data type. How to declare Structure Variables? To declare a variable of type addr , we can write: struct addr addr1; Here, addr1 is a variable of type addr.
More than one object can be declared when we declare a Structure. Variable cannot be defined with a typedef declaration. How to initialize a Structure in C? A Structure variable can be initialized at compile time. Value Value 3 is assigned to student. We have not used any tag name for initializing one Structure variables. But for more than one Structure variable we must use a tag name.
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