Dynamic Memory Allocation in C

Dynamic Memory Allocation in C Most commonly used dynamic memory allocation functions: malloc( ): It is a memory allocation f...


Dynamic Memory Allocation in C


Most commonly used dynamic memory allocation functions:

malloc( ): It is a memory allocation function that allocates requested size of bytes and returns a
pointer to the first byte of the allocated space. The malloc function returns a pointer of type void so we can assign it to any type of pointer. It takes the the following form:

ptr= (cast type *) malloc(byte-size);

where ptr is a pointer of type cast-type. For example, the statement

x=(int *) malloc(10 *sizeof(int)) means that a memory space equivalent to 10
times the size of an int byte is reserved and the address of the first byte of memory allocated is
assigned to the pointer x of int type.




The malloc function can also allocate space for complex data types such as structures. For
example:

ptr= (struct student*) malloc(sizeof (struct student)); where ptr is a pointer of type struct student.

calloc( ): It is another memory allocation function that allocates space for an array of elements, initializes them to zero and then returns a pointer to the memory. This function is normally
used for requesting memory space at run time. It takes the following form:

ptr= (cast type *) calloc(n, element-size);

This statement allocates contiguous space for n blocks, each of size element-size bytes.

realloc( ): realloc is a memory allocation function that modifies the size of previously allocated space. Sometime it may happen that the allocated memory space is larger than what is required or it is less than what is required. In both cases, we can change the memory size already allocated with the help of the realloc function known as reallocation of memory.

 For example, if the original allocation is done by statement

ptr= malloc(size);

then reallocation is done by the statement

ptr=realloc(ptr,newsize); 

which will allocate a new memory space of size newsize to the pointer variable ptr and returns a pointer to the first byte of the new memory block.

COMMENTS

Name

advance-java,2,advancejava,1,aktu entrance exam,1,aktu exam schedule,1,ASP,1,bare machine,1,base register and limit register,1,Basic Computer network questions,1,C Programming,15,C Plus Plus,1,C Programming,2,C Programming MCQ,2,C Programming Questions,2,C programming study material for gate exam,13,Cache Memory,1,CBNST Program,1,Childcare,1,CJ,2,Cloud Computing,1,components of use case diagram,1,Computer architecture based questions for gate exam,11,Computer Network,3,Computer Network Study Material,4,Computer network study material for gate,2,Computer Networks,7,Computer Science Study Material for Gate,20,computer science study material for gate exam,37,content based image retrieval content based image retrieval system,1,contiguous memory allocation,2,Core Java,8,COre Java Interview Questions,1,core java interviews questions,1,cyber crime report,1,Cyber crime status,1,cybercrime and security,1,cybercrime examples,1,Data link Layer Questions,1,Data Mining,1,Data Structure Questions,1,Data Transmission Architecture,1,Data Transmission in wsn,1,DBMS,4,dbms question paper,1,DE,1,Different types of addressing modes,1,Digital Electronics,1,DS,1,dynamic linking,1,dynamic linking in memory management,1,Electroencephalogram,1,File Handling,1,file management in operating system notes,1,FOC,1,Fundamenatl of Computer,1,Gate 2017,5,Gate 2017 Admit card,1,Gate 2017 Exam Schedule,1,Gate 2017 Syllabus,1,gate 2018,1,gate cse study material,1,gate practice set,10,gate study material for computer science,19,Gate study material for computer science 2017,1,GatePreviousYear,1,General,3,HCL Aptitude Test,1,HR Interview Questions,1,HTML,1,Image Processing,1,Important Date of Gate 2017 Exam,1,Information Security Policy,1,internal and external fragmentation,1,JS,1,lagrange's interpolation formula,1,lagrange's interpolation formula examples,1,Looping in C,1,MComputing,1,memory fragmentation,1,memory management,1,Motivational,4,NCER,2,Numerical Techniques Lab,1,OOT,1,Operating System,10,Operating System Objective Questions,4,Operating System Questions Bank,1,Operating system questions for gate,1,Operating System Study material,2,operating system study material for gate exam,16,Operating system tutorial,2,ORACLE,1,page swapping,1,paged memory allocation,1,paged memory allocation in operating system,1,paging technique of memory management .paging technique,1,paging technique of memory management program in c,1,Pointer in C,5,Process based question for gate,1,Quiz on non conventional energy resources,1,Regression testing,1,relocation in memory management,1,relocation registe,1,relocation register,1,resident monitor,1,resident monitor in operating system,1,routing table,1,segmentation in memory management,1,segmentation in memory management in operating system,1,Servlet,1,session tracking,1,session tracking in java,1,session tracking in servlet,1,Software Engineering,8,Software Engineering baes study material for gate,1,software engineering interview questions,1,Software Quality Assurance,3,SPM,1,SQL,1,Structure in C,1,Study Material for gate Computer Science,11,swapping in memory management,1,swapping in operating system,1,TCS Code Vita,1,Technical Questions from DBMS,1,Thrashing in Operating System,1,Threads concept in operating system,1,Tips to Learn Coding,1,Top 30 Core Java Interview Questions with Answer,2,top down approach,1,top down approach in programming,1,Types of operating system,1,UML,1,use case diagram explanation,1,website uses cookies,1,what is cookies website,1,What is process control block ?,1,what is software testing?,1,Wireless Sensor Network,3,worst fit algorithm for memory allocation,1,XML,1,
ltr
item
Computer Science Junction: Dynamic Memory Allocation in C
Dynamic Memory Allocation in C
https://4.bp.blogspot.com/-fV8Gtq12BIQ/Wwp8oEZcB2I/AAAAAAAAAxo/X96L9dWBfdojzTWrnzvxDq4YkIh1HSt-wCLcBGAs/s1600/dynamicmemory.png
https://4.bp.blogspot.com/-fV8Gtq12BIQ/Wwp8oEZcB2I/AAAAAAAAAxo/X96L9dWBfdojzTWrnzvxDq4YkIh1HSt-wCLcBGAs/s72-c/dynamicmemory.png
Computer Science Junction
https://www.computersciencejunction.in/2017/03/dynamic-memory-allocation-in-c.html
https://www.computersciencejunction.in/
https://www.computersciencejunction.in/
https://www.computersciencejunction.in/2017/03/dynamic-memory-allocation-in-c.html
true
425357657003182083
UTF-8
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS PREMIUM CONTENT IS LOCKED STEP 1: Share. STEP 2: Click the link you shared to unlock Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy