issues with identical()

d1 <- data.frame(x=1:3, y=4:6)
d2 <- data.frame(x=1:3, z=4:6)
d3 <- data.frame(x=1:3, y=4:6)
identical(d1, d2)

identical(d1, d3)

From: Jean Eid

Hi all, hope you having a nice day,

I ahve this weird results with identical (probably I am not 
understanding
correctly what it does ...)

I have these two data frames and I issue :

identical(temp, temp1)

[1] FALSE


However, these data frames are Nx2 and when I issue:

identical(temp[,2], temp1[,2])

[1] TRUE

identical(temp[,1], temp1[,1])

[1] TRUE

and the results from str

str(temp)

`data.frame':	7072 obs. of  2 variables:
 $ pub_id  : int  10000 1000 10001 10002 10003 10004 10005 10006 10007
 $ faminc90: int  -2 5998 19900 43000 35000 40000 56538 61000 
36000 39105

str(temp1)

`data.frame':	7072 obs. of  2 variables:
 $ pub_id: int  10000 1000 10001 10002 10003 10004 10005 
10006 10007 10008
 $ faminc: int  -2 5998 19900 43000 35000 40000 56538 61000 
36000 39105

The question is why are the objects different. How else can I 
tell what is
the difference


Thank You

Jean