str_replace_all(x2,"o","A")6.字符删除xstr_remove(x," ")#默认只删第一个str_remove_all(x," ")#专题二:玩转数据框test 0){ print('+')} else { print("-")}i = 1ifelse...= str_detect(samples,"normal");k2ifelse(k2,"normal","tumor")多个条件i = 0if (i>0){ print('+')} else if...(i==0) { print('0')} else if (i0,"+",ifelse(i<0,"-","0"))二、循环语句for循环x <-...(向量)实施相同的操作test <- list(x = 36:33,y = 32:35,z = 30:27);test#返回值是列表,对列表中的每个元素(向量)求均值(试试方差var,分位数quantile