核心模塊 Devel::Peek ?允許我們以C語言的角度來觀察一個(gè)perl 標(biāo)量。

數(shù)組的源代碼定義為

struct xpvav {

char*? xav_array;? /* pointer to first array element */

SSize_t xav_fill;? /* Index of last element present */

SSize_t xav_max;? ? /* max index for which array has space */

IV? ? ? xof_off;? ? /* ptr is incremented by offset */

NV? ? ? xnv_nv;? ? /* numeric value, if any */

MAGIC*? xmg_magic;? /* magic for scalar array */

HV*? ? xmg_stash;? /* class package */

SV**? ? xav_alloc;? /* pointer to malloced string */

SV*? ? xav_arylen;

U8? ? ? xav_flags;

};

試著運(yùn)行命令查看啊

C:\Users>perl? -MDevel::Peek -le "@a=(1,2,3); Dump(\@a)"

SV = IV(0x74bed0) at 0x74bed4

REFCNT = 1

FLAGS = (TEMP,ROK)

RV = 0x26cf97c

SV = PVAV(0x74cc38) at 0x26cf97c

REFCNT = 2

FLAGS = ()

ARRAY = 0x26bf5dc

FILL = 2

MAX = 3

ARYLEN = 0x0

FLAGS = (REAL)

Elt No. 0

SV = IV(0x74bda0) at 0x74bda4

REFCNT = 1

FLAGS = (IOK,pIOK)

IV = 1

Elt No. 1

SV = IV(0x74be70) at 0x74be74

REFCNT = 1

FLAGS = (IOK,pIOK)

IV = 2

Elt No. 2

SV = IV(0x74beb0) at 0x74beb4

REFCNT = 1

FLAGS = (IOK,pIOK)

IV = 3