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malloc is a function in C language used to dynamically allocate memory in heap memory. The syntax is void *malloc(size_t size). It returns a pointer to the allocated memory on success and NULL on failure. Usage includes: 1. The required memory size cannot be determined at compile time; 2. Memory requirements will change as the program executes; 3. A non-contiguous memory block is required. The allocated memory must be released using the free function to prevent memory leaks.
Usage of malloc in C language
What is malloc?
malloc is a function in the C language standard library that is used to dynamically allocate memory in the heap memory.
Syntax
<code class="c">void *malloc(size_t size);</code>
Return type
Purpose
malloc is used to dynamically allocate memory while the program is running. This is useful for situations where the required memory size cannot be determined at compile time.
<code class="c">int *ptr = (int *)malloc(sizeof(int) * 10); if (ptr == NULL) { // 内存分配失败,处理错误 } // 使用分配的内存 ... // 释放分配的内存 free(ptr);</code>Release allocated memory
After using the allocated memory, you must use free function releases it. If not released, the program will leak memory.
<code class="c">free(ptr);</code>
Note
The memory allocated by malloc comes from the heap, which is different from the stack memory. Heap memory is not limited by function scope.
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