R语言 grep()用法及代码示例

R 语言中的 grep() 函数用于在给定字符串的每个元素中搜索模式的匹配项。

用法： 
grep(pattern, x, ignore.case=TRUE/FALSE, value=TRUE/FALSE)
参数： 
pattern: Specified pattern which is going to be matched with given elements of the string. 
x: Specified string vector. 
ignore.case: If its value is TRUE, it ignores case. 
value: If its value is TRUE, it return the matching elements vector, else return the indices vector.

范例1：

Python3


# R program to illustrate
# grep function
 
# Creating string vector
x <- c("GFG", "gfg", "Geeks", "GEEKS")
 
# Calling grep() function
grep("gfg", x)
grep("Geeks", x)
grep("gfg", x, ignore.case = FALSE)
grep("Geeks", x, ignore.case = TRUE)

输出：

[1] 2
[1] 3
[1] 2
[1] 3 4

范例2：

Python3


# R program to illustrate
# grep function
 
# Creating string vector
x <- c("GFG", "gfg", "Geeks", "GEEKS")
 
# Calling grep() function
grep("gfg", x, ignore.case = TRUE, value = TRUE)
grep("G", x, ignore.case = TRUE, value = TRUE)
grep("Geeks", x, ignore.case = FALSE, value = FALSE)
grep("GEEKS", x, ignore.case = FALSE, value = FALSE)

输出：

[1] "GFG" "gfg"
[1] "GFG"   "gfg"   "Geeks" "GEEKS"
[1] 3
[1] 4

相关用法

注：本文由纯净天空筛选整理自nidhi_biet大神的英文原创作品 Find position of a Matched Pattern in a String in R Programming – grep() Function。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。