R語言 names()用法及代碼示例

names()R語言中的函數用於獲取或設置對象的名稱。此函數將對象(即向量、矩陣或 DataFrame )作為參數以及要作為名稱分配給對象的值。傳遞的值向量的長度必須與要命名的對象的長度完全相等。

用法： names(x) <- value

範例1：

# R program to assign name to an object
  
# Creating a vector
x <- c(1, 2, 3, 4, 5)
  
# Assigning names using names() function
names(x) <- c("gfg1", "gfg2", "gfg3", "gfg4", "gfg5")
  
# Printing name vector that is assigned 
names(x)
  
# Printing updated vector
print(x)

輸出：

[1] "gfg1" "gfg2" "gfg3" "gfg4" "gfg5"
gfg1 gfg2 gfg3 gfg4 gfg5 
   1    2    3    4    5 

範例2：

# R program to get names of an Object
  
# Importing Library 
library(datasets) 
    
# Importing dataset 
head(airquality) 
  
# Calling names() function to get names
names(airquality)

輸出：

  Ozone Solar.R Wind Temp Month Day
1    41     190  7.4   67     5   1
2    36     118  8.0   72     5   2
3    12     149 12.6   74     5   3
4    18     313 11.5   62     5   4
5    NA      NA 14.3   56     5   5
6    28      NA 14.9   66     5   6
[1] "Ozone"   "Solar.R" "Wind"    "Temp"    "Month"   "Day"