如何使用for和If来比较两个数据帧？

我想比较数据帧中的变量“Name”，如果值相同，则打印该值，这就是我要做的：

x <- data.frame("SN" = 1:4, "Age" = c(21,15,30,40), "Name" = c("Isa","Dora","Luisa","Daniela"))
x

y <- data.frame("SN" = 1:4, "Age" = c(22,17,36,41), "Name" = c("Isa","Cristian","Peter","Juan"))
y

y$Name

i

for (i in "y$Name"){
  if (i = "x$Name" ){
    print(i)
  }
 next
}

---

x通常，处理此类问题的正确方法是通过
merge
或join语义：

# added stringsAsFactors=FALSE to avoid treating names as factors
x <- data.frame("SN" = 1:4, 
                "Age" = c(21,15,30,40), 
                "Name" = c("Isa","Dora","Luisa","Daniela"),
                stringsAsFactors = FALSE)
y <- data.frame("SN" = 1:4, 
                "Age" = c(22,17,36,41), 
                "Name" = c("Isa","Cristian","Peter","Juan"),
                stringsAsFactors = FALSE)
z <- merge(x, y, by="Name")[["Name"]]
z
[1] "Isa"

#添加了stringsAsFactors=FALSE以避免将名称视为因子
x
intersect（x=x$Name，y=y$Name）
使用for循环：
for（y$Name中的i）{if（i%in%x$Name）{print（i）}}
。从for序列的第一行中删除引号，并将if条件替换为if（x$name[i]==y$name[i]）
。这是一个逐行比较，而不是当前答案或评论给出的结果。可以缩短为
x$name[x$name==y$name]
Thank's，非常有用