Initializing Arrays in C language

init_array.c

/* see also: https://www.gnu.org/software/gnu-c-manual/gnu-c-manual.html */

// assign by index bracket
int nums[5] = { [2] = 10 };           //=> nums: { 0,  0, 10,  0,  0}
int nums[5] = { [2] = 10, [4] = 20}   //=> nums: { 0,  0, 10,  0, 20}

// assign by range
int nums[5] = { [0 ... 4] = 0};       //=> nums: { 0,  0,  0,  0,  0}
int nums[5] = { [0 ... 2] = 1, 2, 3}; //=> nums: { 1,  1,  1,  2,  3}

// assign default values if you don't specify
int nums[5] = { 0 };                  //=> nums: { 0,  0,  0,  0,  0}
int nums[5] = {};                     //=> nums: { 0,  0,  0,  0,  0}

int nums[5] = {0, 1, 2, [4] = 4}      //=> nums: { 0,  1,  2,  0,  4}