perl can't use defined array

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
perl can't use defined array	1.92	0.5	7676	37	28
perl	1.86	0.4	5461	93	4
can't	0.72	0.7	9562	87	5
use	0.63	0.6	7138	31	3
defined	0.5	0.4	633	90	7
array	1.43	0.4	3337	90	5

Keyword	CPC	PCC	Volume	Score
perl can't use defined array	0.12	0.5	9041	14
perl if not defined	1.78	0.1	5640	92
perl reference to array	0.14	1	4204	46
array of array perl	0.89	0.6	7356	77
array definition in perl	0.96	0.7	4624	88
how to declare an array in perl	1.7	0.5	4574	71
perl exist in array	1.1	0.4	7343	14
perl array contains string	1.65	1	7615	55
perl array reference dereference	1.45	0.9	737	1
perl difference between two arrays	0.51	0.6	8605	75
perl array of objects	2	0.3	774	95
perl 2 dimensional array	0.36	0.4	8953	4
array function in perl	0.07	0.2	7800	49
perl array of arrays	1.7	0.6	2368	30
perl add to array	0.46	1	6596	42
perl $#array	1.91	1	9611	27
perl element in array	1.53	0.2	520	23
array operation in perl	0.83	0.2	9751	94
perl append to array	0.71	0.5	8407	71
perl return an array	1.41	0.4	1904	50
perl string to array	0.17	0.6	2327	9