What do square brackets mean in c++

Brackets serve multiple purposes in C: accessing array elements and dereferencing pointers. Define and access elements in vectors, and create range objects. Access elements in an associative container. Specify function parameters. Specify the array size.

Usage of square brackets in C

Usage of square brackets[] in C There are multiple uses, depending on the context:

1. Array subscripting and pointer arithmetic:

• Square brackets are used to access array elements. For example: array[i] accesses the ith element of array array.
• Brackets are also used to dereference pointers. For example: *ptr[i] dereferences the ith element of the array pointed to by the pointer ptr.

2. Vectors and ranges:

• The square brackets are used to define and access elements in the vector. For example: vector<int> v = {1, 2, 3}; v[0] Access the first element of vector v.
• Brackets are also used to create range objects. For example: auto rng = array[start:end]; creates an array range from start to end-1.

3. Associative containers (such as maps and collections):

• Brackets are used to access elements in associative containers. For example: map<string, int> m = {{"a", 1}}; m["a"] Access the value whose key is "a" in map m.

4. Function parameters:

• Square brackets are used to specify function parameters. For example: void func(int arr[]); Define a function that accepts an integer array as a parameter.

5. Array size:

• The square brackets are used to specify the size of the array. For example: int arr[10]; declares an integer array containing 10 elements.

Other usage:

• Square brackets are used for forced type conversion. For example: int i = (int) 3.14; Casts the floating point number 3.14 to an integer.
• Brackets are used to create anonymous structures. For example: struct { int x; int y; } point;

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