startsWith
Does String Start or End With Another String

Description

Tests if a string starts or ends with a another string. The matching is literal: no regular expressions are allowed.

Usage

startsWith(x, prefix)
endsWith(x, suffix)

Arguments

x a character vector to be matched into.
prefix a character vector. startsWith returns TRUE when x starts with prefix.
suffix a character vector. endsWith returns TRUE when x ends with prefix.

Details

These functions are vectorized. The inputs x and prefix (or suffix) are replicated out to the maximum length of the two arguments. Then the matching is done on each element of x with each element of prefix (or suffix).
Value
returns a logical vector with length the maximum length of the two arguments.
See Also
grep, substring
Examples
startsWith(c("thistle", "wheat", "maize"), "t")
## [1]  TRUE FALSE FALSE
endsWith(c("thistle", "wheat", "maize"), "e")
## [1]  TRUE FALSE  TRUE
endsWith(c("thistle", "wheat", "maize"), "ze")
## [1] FALSE FALSE  TRUE

# The matching is literal, no regular expressions are processed: startsWith(c("one", "[a-z]", "[A-Z]"), prefix="[a-z]") ## [1] FALSE TRUE FALSE

# Arguments are replicated out to maximum length: startsWith(c("A", "A", "B", "B"), prefix=c("A", "B")) ## [1] TRUE FALSE FALSE TRUE endsWith("tomato", suffix=c("a", "e", "i", "o", "u")) ## [1] FALSE FALSE FALSE TRUE FALSE

Package base version 6.1.4-13
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