Syntax error How to extract the names of list elements in R?

How to extract the names of list elements in R?

The names of list elements can be extracted by using the names function. For example, if we have a list defined as List that contains three elements with names element1, element2, and element3 then then these names can be extracted from the List by using the below command:

names(List)

Example1

Live Demo

> List1<-list(x1=rnorm(50),x2=rnorm(50,1,0.28),x3=rnorm(50,5,2.1))
> List1

Output

$x1
[1] -0.04518909 -0.22779868 0.24339595 -0.86189295 -0.73387277 -0.75313131
[7] 0.39694608 2.30565359 0.55670193 0.21973762 0.62968128 -0.90936921
[13] 1.33946741 -0.16315751 0.31357793 0.40365980 -0.23639612 -2.48749453
[19] 0.52152768 -1.57059863 0.51728464 0.98177111 0.65475629 0.23715538
[25] -0.71796609 -0.42731839 0.32335282 -0.90013122 -0.84549927 -0.88358214
[31] -0.32066379 -0.98945433 0.42469849 -1.63095343 0.32584448 0.10947333
[37] 0.23486625 0.28166351 1.18432843 0.94828212 0.09452671 0.56618262
[43] 0.52839533 1.22136242 0.76011311 0.11757345 2.47459913 -0.47890572
[49] -1.91918520 -0.02408708

$x2
[1] 0.8270975 0.9756136 1.1292744 1.0656721 0.7703431 0.8769942 1.1293051
[8] 1.0581120 1.0815165 1.2847627 0.6654920 1.2342987 0.6837453 1.2018498
[15] 1.0908703 1.1193189 0.5471691 1.0213345 0.8050452 0.4815627 0.6849457
[22] 0.8577580 1.1381807 1.0131761 1.2062184 0.7610613 1.3568787 0.9533896
[29] 1.2557551 0.4617964 0.8776077 1.3058164 1.1131230 1.2142810 0.9978407
[36] 0.7247716 1.4211604 0.5994001 0.7525555 1.4627048 0.7734563 0.8280289
[43] 0.9735345 1.0476358 1.1781612 0.8641444 1.0304007 0.6046310 0.8035452
[50] 0.7185106

$x3
[1] 2.617699 6.486300 3.796717 2.448953 8.561896 6.948493 6.174320 5.890213
[9] 6.333487 1.866408 4.988860 5.306587 6.862673 2.881893 2.172200 3.583765
[17] 3.830627 3.403771 6.404305 4.417270 4.538683 2.788276 4.869081 7.097852
[25] 2.967966 4.711434 5.088199 8.753127 5.219092 6.472948 3.698116 3.735600
[33] 5.301249 3.958626 2.951177 1.139676 5.973805 3.137057 5.817388 6.123433
[41] 5.380026 8.153839 4.524674 2.266312 2.914673 3.633610 5.324451 5.095410
[49] 5.221360 1.832700

Example

> names(List1)

Output

[1] "x1" "x2" "x3"

Example2

Live Demo

> List2<-list(x1=rpois(50,5),x2=rpois(50,1),x3=rpois(50,5),x4=rpois(50,8),x5=rpois(50,10))
> List2

Output

$x1
[1] 7 7 6 4 2 5 5 7 7 4 9 3 2 3 1 7 3 5 4 6 7 4 7 8 2
[26] 2 9 5 8 3 7 6 4 11 4 7 4 6 6 4 3 7 5 4 7 4 7 5 4 3

$x2
[1] 1 0 1 2 0 2 2 0 2 3 1 3 2 1 1 1 1 2 1 2 1 1 0 0 0 0 3 0 1 0 1 1 3 0 1 0 2 1
[39] 1 1 0 0 0 0 2 2 1 0 2 1

$x3
[1] 3 7 7 8 2 4 6 7 8 3 6 8 2 6 4 5 6 6 4 4 9 4 5 4 5
[26] 4 5 5 8 0 5 6 3 3 6 12 2 7 4 4 7 6 7 2 6 7 11 13 5 6

$x4
[1] 7 7 8 15 5 6 12 12 6 6 4 9 11 12 6 11 15 13 10 8 9 6 10 12 10
[26] 8 8 8 8 9 6 9 7 9 8 5 5 9 10 8 5 6 8 12 8 11 9 8 9 6

$x5
[1] 9 10 9 9 6 7 8 6 13 12 14 7 8 13 8 8 10 8 10 10 9 7 9 7 4
[26] 11 5 7 18 10 12 6 11 13 13 5 12 15 9 6 5 12 9 10 10 4 11 6 12 15

Example

> names(List2)

Output

[1] "x1" "x2" "x3" "x4" "x5"

Example3

Live Demo

> List3<-list(x1=runif(50,2,5),x2=runif(50,1,5),x3=runif(50,5,10))
> List3

Output

$x1
[1] 4.413341 3.318683 2.450609 3.117884 3.347430 2.167973 4.473528 3.308317
[9] 2.891431 3.259983 2.101081 2.489383 2.727202 4.103531 2.061813 2.126091
[17] 4.590316 4.890000 2.725137 4.086082 3.798446 2.682532 3.600169 4.228952
[25] 2.264763 4.732312 3.053867 2.090457 3.528672 3.097195 2.808085 4.666389
[33] 3.644389 4.517354 4.119483 4.859402 3.091996 2.886587 4.989477 2.945724
[41] 4.262805 2.757937 2.320727 3.989926 2.747881 3.432197 4.045197 2.313279
[49] 2.873494 4.004079

$x2
[1] 3.863761 3.060900 3.088654 1.429419 1.501166 3.371164 3.016494 2.433578
[9] 3.644674 2.931639 4.553203 1.309591 1.696542 4.647760 4.973822 3.630334
[17] 1.494571 2.141640 3.337546 3.793574 3.544146 3.906353 3.318471 1.653554
[25] 4.452764 2.863841 3.988762 4.696605 2.372169 3.913032 4.068302 4.211055
[33] 2.796389 4.569563 1.362797 1.360992 1.562173 3.539244 1.588572 2.740451
[41] 1.512468 2.503382 1.298349 1.508630 2.195898 4.040723 2.272298 4.225725
[49] 4.682531 3.030588

$x3
[1] 7.904580 9.373170 5.687662 5.615320 6.170858 9.833555 6.421968 8.256569
[9] 5.255653 9.225753 6.719730 9.973355 7.186546 6.466654 7.712851 7.791231
[17] 9.460951 8.485921 6.945822 6.276568 5.247020 8.141602 6.575557 7.804101
[25] 7.483326 7.482139 8.670358 5.600923 6.953811 8.090939 9.176059 7.189967
[33] 5.356993 8.398447 5.429305 7.351870 6.970362 6.780346 7.637896 8.434442
[41] 9.261975 5.176213 8.207120 5.733510 7.102484 7.958931 5.799031 7.223153
[49] 5.255746 5.394654

Example

> names(List3)

Output

[1] "x1" "x2" "x3"

Example4

Live Demo

> List4<-list(y1=rexp(50,1.12),y2=rexp(50,2.1))
> List4

Output

$y1
[1] 0.806148350 1.458187265 0.534007093 0.950131273 0.217697643 0.349654709
[7] 0.874155289 2.004103178 0.362298127 0.533686567 0.611537599 0.136836959
[13] 0.198465017 0.516533088 0.705214297 0.348598974 0.385648527 0.257238782
[19] 0.131113534 0.456706525 4.077398554 0.501530183 1.094008447 0.279010694
[25] 2.271581539 0.342538455 0.077849912 0.502802631 1.844349116 0.297917889
[31] 0.081726119 1.545759146 1.119755295 0.006217782 1.711755760 0.227284939
[37] 1.391966260 0.845130298 1.719655529 0.519416726 0.898552797 0.208143165
[43] 2.520577533 1.670047493 0.756593752 0.361542577 2.468861275 0.280330950
[49] 0.336729084 6.532385077

$y2
[1] 0.139012937 0.751480073 0.071020098 0.786773500 0.372965729 0.037590902
[7] 0.167700221 0.092755225 0.787360131 0.107568293 2.268001886 0.444335844
[13] 0.074739241 0.151111998 0.184172284 0.581389785 0.014686120 0.820748947
[19] 0.107117694 0.327100046 0.200850286 0.076522915 0.201419763 0.122467053
[25] 0.192721591 0.189551687 0.278166513 0.299343658 0.149084151 0.958924542
[31] 0.034754787 0.004645119 0.670121429 1.347222694 0.642560074 0.023936619
[37] 0.575837008 0.768578674 0.196833013 2.178089408 0.331298845 1.839747737
[43] 0.594427700 0.700286120 0.224447412 0.523475388 0.364124369 0.617526646
[49] 0.482226880 1.318312322

Example

> names(List4)

Output

[1] "y1" "y2"
Updated on: 2020-11-21T06:07:43+05:30

3K+ Views

Kickstart Your Career

Get certified by completing the course

Get Started
Advertisements