Most voted "allocation" questions
Allocation refers to interpreted languages such as C and C++, which dynamic memory allocation is part of data management and security.
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23
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answer9539
viewsWhat is the difference between "calloc()" and "malloc()"?
What the function calloc() makes the malloc() Doesn’t it? Why is it hardly used?
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11
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answers1211
viewsConcepts of Mesomorphic Allocation and Liberation in C#
I’m making a web application that has a finite recursive loop. But during the process the memory consumption is constantly growing and at the end Visual Studio has more than 2 Gigas of memory use. I…
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11
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answers462
viewsHow to allocate dynamically when I don’t know how many positions I will use in C?
In a part of the code I need to transform an integer into binary and store it in a character array, however, I don’t know which integer I will receive to transform into binary, so I don’t know how…
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10
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answers42472
viewsError Segmentation fault (core dumped)
I’m getting the following error message in my code: Segmentation fault (core dumped) Another thing is, when I performed the same function operation preenche in the main, using ficha.name in place of…
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10
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answers158
viewsWhat happens to memory when "realloc()" reallocates a memory block to a value less than the original?
Suppose I allot a dynamic matrix of 10 ints and assign some values values to it, then I use the function realloc() to reallocate the matrix to 3 ints, what happens to the other 7 ints, they will be…
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9
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answers1582
viewsWhat is the difference in the syntax ptr = (int*) malloc (sizeof(int)) and ptr = malloc (sizeof(int))?
I have a question about dynamic allocation in C. At the time of allocating memory I have seen these two types of syntax: ptr = (int*) malloc (sizeof(int)); ptr = malloc (sizeof(int)); But I don’t…
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8
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answers747
viewsIs malloc typecast recommended?
I have read that it is not advisable to do the Typecast of malloc when we are allocating memory to a new pointer variable, and many websites and books teach this practice in memory allocation, it…
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7
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answer767
viewsChange of char variable content
I’m having trouble working with files and handling char. CODE char *fileTipoDespesaDefault; char *fileTipoPagamentoDefault; FILE *fileTipoDespesa; FILE *fileTipoPagamento; /** * tipos : 1 =>…
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7
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answers330
viewsDynamic allocation and runtime of functions
When we use any of the dynamic allocation functions in C (malloc, calloc, realloc, etc.), within a function that is called by main, will the memory remain allocated at the end of the execution of…
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7
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answer566
viewsDynamic Memory Allocation X vector
I was studying this subject in C, and in most of the places I look for, one of the examples of using this resource is when you’re going to create a vector whose size you don’t know. Example: int…
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6
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answers830
viewsHow to allocate program memory and storage before running my application in Wince?
I am reprogramming a C# application to run on Windows CE, but my machine has little memory. Therefore, I need to allocate the appropriate amount of processing memory (program memory) and storage…
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6
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answers2673
viewsHow big is a memory address?
What size of a memory address? I think a memory address has 32 bits, but I’m seeing it in a Debugger one int, where he separated 4 addresses for him. So, an address is equal to 32 bits? Because…
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6
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answers475
viewsMalloc improperly reserving memory?
I am studying dynamic memory allocation and came across an error that apparently the compiler is not warning about. The code is very simple: int *ptr = (int *) malloc(sizeof(int)); ptr[0] = 5;…
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6
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answer217
viewsWhat is behind the malloc() dynamic allocation function?
What mechanisms the function malloc() uses in practice to manage dynamic memory allocation in a program?
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6
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answer80
viewsHow long is the data allocated to functions?
In one language, (I don’t know if there’s any difference in others, but you can consider Javascript) when I have this situation: function a() { b(); } function b() { c(); } function c() { d(); }…
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6
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answers146
viewsPointer changes address when exiting function
When performing a dynamic allocation of a vector or matrix in C, the pointer for that allocation changes address when leaving the function, before it was pointing to the initial address of the…
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6
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answers198
viewsstrcpy is merging numeric format with other chars
I don’t know if I made myself clear in the title, but when using strcpy() to copy a char* to another when I put a format like this "teste" it works normally, but when I put a string 3 letter format…
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5
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answers295
viewsWhy did a dynamic array work without the use of malloc()?
Follow the code passage below: int main(void) { int tam, vet[tam]; printf("\ndigite tam: "); scanf("%d", &tam); return 0; } I didn’t know this worked, because I’m typing the vector size at…
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5
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answer332
viewsProblems with dynamic allocation
In an exercise I need to make a record of a struct possibly declared as follows:. typedef struct Locatarios { char nomeLocatario[MAX_NOME]; int codigoLoc; float valorAluguel; } Locatarios; It is…
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5
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answers540
viewsColo allocate a memory based on the size the user typed
How can I get it right after the user enters a string the program counts the number x of characters of this and allocate X bytes to it? I am not able to do it, I tried for example to make after the…
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answers456
viewsMemory allocation for pointers
I’ve been reading and studying on pointers and came across the following quote in a book: "Although it is possible to use them as vectors, pointers do not have their own memory. You can only use…
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5
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answers724
viewsDelete a space allocated by malloc
First I allotted 6 spaces of 52 bytes belonging to a struct in memory: lista = malloc(6 * sizeof(registro)); In practice to access them via pointer is done: lista[0], lista[1], lista[2]... And how I…
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5
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answer776
viewsAllocation Space for Mysql Fields
First I create the model in my application, then the Entity Framework generates the SQL for the table creation. The first statement generates a column with the type varchar(20), the second generates…
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5
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answer1146
viewsDynamic stack - C
I’m studying dynamic stack from the code below: #include <stdio.h> #include <stdlib.h> #define tam 50 // ---- Estruturas para os tipos…
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5
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answers1148
viewsDynamic allocation in C - allocating without knowing the total amount of elements
I have a question about the dynamic allocation in c, as to the use of the function malloc(). If we take, for example, a case of registration of a full name, as we have no way of knowing the amount…
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4
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answer329
viewsPointer of struct in C
What happens is this, within the function ins_ult() I can change the value of root->data, but outside the function the value remains NULL. I’m passing the parameter the wrong way or using the…
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4
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answers14165
viewsDynamic allocation for struct
I need to dynamically allocate space for a structure, but I am not able and I do not know my error is at the time of the statement or allocation, follow the functions consistent with the statement.…
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4
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answers69
viewsHow should these variables end correctly without having a chance of memory Leak?
What is the right way to use the free() in that case, where ls_options will contain several ls_buffer_send? char **ls_options = (char**) malloc (200*sizeof(char)); char *ls_buffer_send = (char*)…
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4
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answers117
viewsHow do I use free() and return the same content?
I wanted to use the free() in ls_retorna in the following function, how could you do it with the best way? char* MemCpyX(char *as_origem, int an_inicio, int an_quantidade) { char *ls_retorno =…
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4
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answer1450
viewsManipulating batteries in C
I’m a C beginner and I have the following exercise: The Parking Stationhere contains a single boulevard that guards up to ten cars. There is only one entry/exit in the parking lot, in one edge of…
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answers408
viewsUse free() without malloc()?
May cause some problem in using the free() on a pointer that was not allocated with malloc() beyond the necessity itself? void funcao (int par) { char *palavra; if(par%2 == 0) { palavra =…
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4
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answer1523
viewsCorrect use of free() in function?
How to use function free() when it is used within a function, in that function Gero a dynamic vector and the function itself will be the return, example: int* copia(int *vet, int tam) { int i,…
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4
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answer96
viewsWhy not give Segmentation fault when writing to a "char *" without allocating memory?
My question is whether the compiler automatically allocates memory to the variable s1 char *s1; char s2[20]; //s1=(char*)malloc (sizeof(char)*20); s1="palavra1"; strcpy (s2,"palavra2");…
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answers267
viewsBehaviour of malloc(1) in C
If I use char *char_commandout = (char *) malloc(1);, the allocated byte will store the " 0" at position 0 of the vector or will allocate a space for the value I want to store (at position 0) and…
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4
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answers501
viewsWhen to dynamically allocate memory?
In C++ you can easily declare an object or variable like this: tipo_da_variável nome_da_variável; This type of statement is the easiest to use, but you can also use the new to dynamically allocate…
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answers522
viewsDynamic allocation of vectors
Follows the statement: Make a program that reads keyboard numbers and store them on one dynamically allocated array. The user will type in a sequence of numbers, no quantity limit. The numbers will…
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answers221
viewsHow to transform my code with static memory struct to C dynamics?
The exercise asks me to read information in a file, being them, Cpf, name, email and age of several people store in a struct, order in ascending order by age, if equal ages by Cpf, and print in…
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4
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answer38
viewsUse of delete in an abstract class pointer
Reading the book A tour of C++, in a section on memory leakage, when I came across 3 statements regarding the code below: The implementation of Smiley may fail to delete pointer to mouth. The…
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answer111
viewsDoubt in dynamic memory allocation
In the code below, release B memory also releases from A? int* A = new int[4]; int *B = A; delete[] B;
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3
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answer218
viewsC++ Dynamic Pointer Allocation
I am needing to create a protection routine in the removal function. Why it gives error when removing the last item? The function: // Remover o primeiro cliente void cadRemover(){ lista=ini; //…
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answers211
viewsProgram using malloc twice
Why this program that divides a number into decimal notation, transforms it into binary notation and prints the number on the screen in the correct sequence (from bit most significant for the least…
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3
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answers1697
viewsRemove element from a chained list
I am implementing a chained list of type "with head". It follows struct referring to the list and its creation in main() struct lista{ int info; struct lista *prox; }; typedef struct lista Lista;…
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3
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answers176
viewsWhy am I getting Segmentation fault dynamic matrix?
They say not to cast on the return of function malloc, but this code there if the dimension of the matrix is above 4, it gives Segmentation fault from matriz[5][1] in the count: int main(){ int…
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3
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answers233
viewsError: "invalid operands to Binary Expression ('char *' and 'char *')"
I need to create a string which contains "Mr: n" and the name of the person concerned (pessoa->nome). char* endereca(Pessoa* pessoa) { if(pessoa->sexo == 'M') { char *msg; msg =…
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answer75
viewsVector problem with dynamic allocation
The intention of this program that I am doing is to serve as if it were a banking system in which the amount of accounts to be created does not have a previously defined amount. In the main(), i…
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3
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answer202
viewsProblem with dynamic allocation - realloc()
I’m doing a program that works as a payroll system, but I’m having trouble with the dynamic allocation part. The program runs only once and stops. No int(main) i put: printf("Sizeof :…
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3
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answer62
viewsProblems with dynamic matrix allocation
I’m trying to dynamically allocate a matrix, but I’m having some problems with running time and I’m also getting a Warning of GCC in the compilation time. Follow the code below for a better analysis…
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3
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answers84
viewsError of memory allocation
I am creating a C script to classify a triangle according to the 3 sides passed. For this I use three distinct variables, lado1, lado2 and lado3, as illustrated by the code below: #include…
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answer111
viewsHow to allocate in contiguous memory a structure that contains 1 vector with user defined size?
I was wondering how to answer this issue and I came to the conclusion that I would need a data structure with: the size of a set a previously reported size vector It would be something like the…
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3
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answer125
viewsWhere does the memory space required for each element in a C string array come from?
In C, you can group a set of string's, which are arrays of char's within a array without having to define 2 dimensions for this? That’s why you use a array pointer char's and simply defines the…