資料結構
網路
關係資料庫管理系統
作業系統
Java
MS Excel
iOS
HTML
CSS
Android
Python
C 程式設計
C++
C#
MongoDB
MySQL
Javascript
PHP
物理學
化學
生物學
數學
英語
經濟學
心理學
社會學
時尚研究
法律研究如何在 R 中檢查字串是否為小寫或大寫？
我們可以使用 str_detect 函式來檢查單個字串或字串向量是否為小寫或大寫。 除了 str_detect 函式之外，我們還需要使用 upper 或 lower 來檢查字串是否為小寫或大寫，並且輸出將以 TRUE 或 FALSE 的形式返回，如果字串為小寫，並且我們將 lower 與 str_detect 函式一起使用，則輸出將為 TRUE，反之亦然。
示例
x1<-letters[1:26] x1
輸出
[1] "a" "b" "c" "d" "e" "f" "g" "h" "i" "j" "k" "l" "m" "n" "o" "p" "q" "r" "s" [20] "t" "u" "v" "w" "x" "y" "z"
示例
str_detect(x1,"[[:upper:]]")
輸出
[1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [25] FALSE FALSE
示例
x2<-LETTERS[1:26] x2
輸出
[1] "A" "B" "C" "D" "E" "F" "G" "H" "I" "J" "K" "L" "M" "N" "O" "P" "Q" "R" "S" [20] "T" "U" "V" "W" "X" "Y" "Z"
示例
str_detect(x2,"[[:upper:]]")
輸出
[1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [16] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
示例
x3<-"india" x3
輸出
[1] "india"
示例
str_detect(x3,"[[:upper:]]")
輸出
[1] FALSE
示例
x4<-c("abc","abcd","abcde","bacdef")
x4輸出
[1] "abc" "abcd" "abcde" "bacdef"
示例
str_detect(x4,"[[:upper:]]")
輸出
[1] FALSE FALSE FALSE FALSE
示例
x5<-c("AK", "AL", "AR", "AS", "AZ", "CA", "CO", "CT", "DC", "DE", "FL", "GA", "GU", "HI", "IA", "ID", "IL", "IN", "KS", "KY", "LA", "MA", "MD", "ME", "MI", "MN", "MO", "MP", "MS", "MT", "NC", "ND", "NE", "NH", "NJ", "NM", "NV", "NY", "OH", "OK", "OR", "PA", "PR", "RI", "SC", "SD", "TN", "TX", "UM", "UT", "VA", "VI", "VT", "WA", "WI", "WV", "WY")
x5輸出
[1] "AK" "AL" "AR" "AS" "AZ" "CA" "CO" "CT" "DC" "DE" "FL" "GA" "GU" "HI" "IA" [16] "ID" "IL" "IN" "KS" "KY" "LA" "MA" "MD" "ME" "MI" "MN" "MO" "MP" "MS" "MT" [31] "NC" "ND" "NE" "NH" "NJ" "NM" "NV" "NY" "OH" "OK" "OR" "PA" "PR" "RI" "SC" [46] "SD" "TN" "TX" "UM" "UT" "VA" "VI" "VT" "WA" "WI" "WV" "WY"
示例
str_detect(x5,"[[:upper:]]")
輸出
[1] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [16] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [31] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE [46] TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE TRUE
示例
x6<-c("alabama", "alaska", "american samoa", "arizona", "arkansas", "california", "colorado", "connecticut", "delaware", "district of columbia", "florida", "georgia", "guam", "hawaii", "idaho", "illinois", "indiana", "iowa", "kansas", "kentucky", "louisiana", "maine", "maryland", "massachusetts", "michigan", "minnesota", "minor outlying islands", "mississippi", "missouri", "montana", "nebraska", "nevada", "new hampshire", "new jersey", "new mexico", "new york", "north carolina", "north dakota", "northern mariana islands", "ohio", "oklahoma", "oregon", "pennsylvania", "puerto rico", "rhode island", "south carolina", "south dakota", "tennessee", "texas", "u.s. virgin islands", "utah", "vermont", "virginia", "washington", "west virginia", "wisconsin", "wyoming")
x6輸出
[1] "alabama" "alaska" [3] "american samoa" "arizona" [5] "arkansas" "california" [7] "colorado" "connecticut" [9] "delaware" "district of columbia" [11] "florida" "georgia" [13] "guam" "hawaii" [15] "idaho" "illinois" [17] "indiana" "iowa" [19] "kansas" "kentucky" [21] "louisiana" "maine" [23] "maryland" "massachusetts" [25] "michigan" "minnesota" [27] "minor outlying islands" "mississippi" [29] "missouri" "montana" [31] "nebraska" "nevada" [33] "new hampshire" "new jersey" [35] "new mexico" "new york" [37] "north carolina" "north dakota" [39] "northern mariana islands" "ohio" [41] "oklahoma" "oregon" [43] "pennsylvania" "puerto rico" [45] "rhode island" "south carolina" [47] "south dakota" "tennessee" [49] "texas" "u.s. virgin islands" [51] "utah" "vermont" [53] "virginia" "washington" [55] "west virginia" "wisconsin" [57] "wyoming"
示例
str_detect(x6,"[[:upper:]]")
輸出
[1] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [13] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [25] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [37] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE [49] FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
更新於: 2020-10-16
3K+ 瀏覽量
廣告