Find Position of First Occurrence Of a String

Returns the numeric position of the first occurrence of a substring within a string. If the search string is not found, the result will be NA.

Usage

strPos(x, pattern, pos = 1)

Arguments

x

a character vector in which to search for the pattern, or an object which can be coerced by as.character to a character vector

pattern

character string (search string) containing the pattern to be matched in the given character vector. This can be a character string or a regular expression.

pos

integer, defining the start position for the search within x. The result will then be relative to the begin of the truncated string. Will be recycled.

Value

a vector of the first position of pattern in x

Details

This is just a wrapper for the function regexpr().

See also

strChop(), regexpr()

string-overview for an overview of all string utilities in pharos.

Examples

strPos(x=rownames(mtcars), pattern="y")
#>  [1] NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA  4 NA NA  3  3 NA NA NA NA
#> [26] NA NA NA NA NA NA NA

# first t, starting with position 4
strPos(x=rownames(mtcars), pattern="t", pos=4)
#>  [1] NA NA NA  3  3  4  1 NA NA NA NA NA NA NA 11  9 NA  1 NA  2  2 NA NA NA  1
#> [26]  1 NA NA  6 NA  4 NA