在 R 编程中检查向量对象的存在 - is.vector()函数

R 语言中的is.vector()函数用于返回 TRUE，如果给定的向量是指定的模式，除了名称之外没有其他属性。否则返回 FALSE。

Syntax: is.vector(x, mode = “any”)

Parameters:
x: R object
mode: character string naming an atomic mode or “list” or “expression” or “any”

示例 1：

# R program to illustrate
# is.vector function
  
# Initializing some data types
x <- c(a = 1, b = 2)
y <- list(c("GFG", "gfg"), matrix(c(1, 2, 3)))
z <- "Geeks"
  
# Calling is.vector() function
is.vector(x)
is.vector(y)
is.vector(z)

输出：

[1] TRUE
[1] TRUE
[1] TRUE

示例 2：

# R program to illustrate
# is.vector function
  
# Initializing some data types
x <- c(a = 1, b = 2)
y <- list(c("GFG", "gfg"), matrix(c(1, 2, 3)))
z <- "Geeks"
  
# Calling is.vector() function
is.vector(x,  mode = "list")
is.vector(x,  mode = "expression")
is.vector(x,  mode = "any")
is.vector(y,  mode = "list")
is.vector(y,  mode = "expression")
is.vector(y,  mode = "any")
is.vector(z,  mode = "list")
is.vector(z,  mode = "expression")
is.vector(z,  mode = "any")

输出：

[1] FALSE
[1] FALSE
[1] TRUE
[1] TRUE
[1] FALSE
[1] TRUE
[1] FALSE
[1] FALSE
[1] TRUE