检查两个数据帧在R中的相同行和列是否具有相同的值

df1 <- data.frame(a = c(1, 2, 3), b = c("x", "y", "z"))
df2 <- data.frame(a = c(1, 2, 3), b = c("x", "y", "z"))

identical(df1, df2)

df1 <- data.frame(a = c(1, 2, 3), b = c("x", "y", "z"))
df2 <- data.frame(a = c(1, 2, 3), b = c("x", "y", "z"))

all.equal(df1, df2)

df1 <- data.frame(a = c(1, 2, 3), b = c("x", "y", "z"))
df2 <- data.frame(a = c(1, 2, 3), b = c("x", "y", "z"))

df1 == df2

     a    b
[1,] TRUE TRUE
[2,] TRUE TRUE
[3,] TRUE TRUE