[R] get() return nothing

[Duncan Murdoch]

On 11/02/2017 1:33 PM, Fix Ace via R-help wrote:
> Hello, there,
> I wrote a loop to check the dimension of all the .txt dataframes:> ls()
>  [1] "actualpca.table" "b4galnt2"        "b4galnt2.txt"    "data"
>  [5] "galnt4"          "galnt4.txt"      "galnt5"          "galnt5.txt"
>  [9] "galnt6"          "galnt6.txt"      "glyco"           "glyco.txt"
> [13] "i"               "mtscaled"        "newsig.table"    "nicepca"
> [17] "pca"             "sig.txt"         "st3gal3"         "st3gal3.txt"
> [21] "st3gal5"         "st3gal5.txt"     "st6gal1"         "st6gal1.txt"
>> for(i in ls(pattern="txt")){dim(get(i))}
>>
> If I check individual ones, they are ok:
>> dim(get("galnt4.txt"))
> [1] 8 3
>>
> could anyone help me to figure out why it did not work with a loop?
> Thanks a lot!

It's the difference between

for (i in 1:10) i

(which prints nothing) and

for (i in 1:10) print(i)

Duncan Murdoch