如何在R中的head（）函数用于多个数据帧？

Question

How can I use the head() function for multiple files at the same time?

The following script does not work.

head(c(mtcars, airquality))

$mpg
 [1] 21.0 21.0 22.8 21.4 18.7 18.1 14.3 24.4 22.8 19.2 17.8 16.4 17.3 15.2 10.4 10.4
[17] 14.7 32.4 30.4 33.9 21.5 15.5 15.2 13.3 19.2 27.3 26.0 30.4 15.8 19.7 15.0 21.4

$cyl
 [1] 6 6 4 6 8 6 8 4 4 6 6 8 8 8 8 8 8 4 4 4 4 8 8 8 8 4 4 4 8 6 8 4

$disp
 [1] 160.0 160.0 108.0 258.0 360.0 225.0 360.0 146.7 140.8 167.6 167.6 275.8 275.8
[14] 275.8 472.0 460.0 440.0  78.7  75.7  71.1 120.1 318.0 304.0 350.0 400.0  79.0
[27] 120.3  95.1 351.0 145.0 301.0 121.0

$hp
 [1] 110 110  93 110 175 105 245  62  95 123 123 180 180 180 205 215 230  66  52  65
[21]  97 150 150 245 175  66  91 113 264 175 335 109

$drat
 [1] 3.90 3.90 3.85 3.08 3.15 2.76 3.21 3.69 3.92 3.92 3.92 3.07 3.07 3.07 2.93 3.00
[17] 3.23 4.08 4.93 4.22 3.70 2.76 3.15 3.73 3.08 4.08 4.43 3.77 4.22 3.62 3.54 4.11

$wt
 [1] 2.620 2.875 2.320 3.215 3.440 3.460 3.570 3.190 3.150 3.440 3.440 4.070 3.730
[14] 3.780 5.250 5.424 5.345 2.200 1.615 1.835 2.465 3.520 3.435 3.840 3.845 1.935
[27] 2.140 1.513 3.170 2.770 3.570 2.780

Expectation:

To see the first six lines of mtcars , the fist six lines of airquality , and so on if I use other files as well.

Answer 1

将项目放在列表中，然后使用sapply遍历它们的调用头。

sapply(list(mtcars, airquality), head, n = 6)