what is the meaning of following code?

s_box_table = [ 99,124,119,123,242,107,111,197,48,1,103,43,254,215,171,118 ...

202,130,201,125,250,89,71,240,173,212,162,175,156,164,114,192 ...

183,253,147,38,54,63,247,204,52,165,229,241,113,216,49,21 ...

4,199,35,195,24,150,5,154,7,18,128,226,235,39,178,117 ...

9,131,44,26,27,110,90,160,82,59,214,179,41,227,47,132 ...

83,209,0,237,32,252,177,91,106,203,190,57,74,76,88,207 ...

208,239,170,251,67,77,51,133,69,249,2,127,80,60,159,168 ...

81,163,64,143,146,157,56,245,188,182,218,33,16,255,243,210 ...

205,12,19,236,95,151,68,23,196,167,126,61,100,93,25,115 ...

96,129,79,220,34,42,144,136,70,238,184,20,222,94,11,219 ...

224,50,58,10,73,6,36,92,194,211,172,98,145,149,228,121 ...

231,200,55,109,141,213,78,169,108,86,244,234,101,122,174,8 ...

186,120,37,46,28,166,180,198,232,221,116,31,75,189,139,138 ...

112,62,181,102,72,3,246,14,97,53,87,185,134,193,29,158 ...

225,248,152,17,105,217,142,148,155,30,135,233,206,85,40,223 ...

140,161,137,13,191,230,66,104,65,153,45,15,176,84,187,22];

s_box_out = s_box_table(s_box_in + 1);

Answer 1

[Image Analyst]

If s_box_in is an integer greater than 0, that code extracts one number from s_box_table.

If s_box_in is a vector, it extracts a bunch of numbers - whatever s_box_in specifies.