R substring - 从字符串中提取日期

Question

我有一个字符变量，列出如下值：

        default: cout << "\nInvalid hexadecimal digit " << *i;

我想只提取日期（76GA14, Week 1, 05/13/2014, ABC 76GA14, Week 4, 02/08/2016, ABC 76GA15, Week 3, 09/02/2016, ABC 76GA15, Week 8, 01/19/2015, ABC 76GA16, Week 1, 11/28/2018, ABC 76GA18, Day 0, 12/07/2015, ABC 76GA18, Day 2 End, 11/22/2016, ABC 76GA17, W4 end 6DNV118, 07/06/2016, ABC ... ）并设置创建一个包含这些值的新变量列。

Answer 1

有很多方法可以做到这一点。

这是我的建议：

charVector <- c("76GA14, Week 1, 05/13/2014, ABC",
                "76GA14, Week 4, 02/08/2016, ABC",
                "76GA15, Week 3, 09/02/2016, ABC",
                "76GA15, Week 8, 01/19/2015, ABC",
                "76GA16, Week 1, 11/28/2018, ABC")

newVariable <- sapply(strsplit(charVector, ", "), "[", 3)