char <- c("I","am","a","boy","and","i","lile","coding")
grep("^a$",char)
結果爲: 3
char <- c("I","am","a","boy","and","i","lile","coding")
grep("^a$",char)
結果爲: 3
學習筆記,僅供參考 repeat循環 repeat循環可以重複執行相同的代碼,直到滿足停止條件。 語法 repeat { 命令行 if(關係表達式) { break #關係表達式