Question

创建不区分大小写的if语句的最佳方法是什么？

例如，如果我有<img src="https://cdn2.iconfinder.com/data/icons/mixed-vol-7/74/Untitled-1-11-08-07-17-512.png" onClick="maximizeorMinimize(this)" width="15" height="15" style="margin-left: 55%;" title="Maximize"> <table id="maximizableTable"> <tr><td>Text</td><td>Text</td></tr> <tr><td>Text</td><td>Text</td></tr> <tr><td>Text</td><td>Text</td></tr> <tr><td>Text</td><td>Text</td></tr> </table> <script> var table = document.getElementById("maximizableTable"); var maximized = false; function maximizeorMinimize(elem){ if(!maximized){ table.style.width = "100%"; table.style.height = "100%"; table.style.top = "20%"; table.style.left = "0"; table.style.fontSize = "2em"; elem.style.marginLeft = "60%"; elem.src = "data:image/png;base64,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"; elem.width = "50"; elem.height = "50"; elem.title = "Minimize"; maximized = true; } else { table.style.width = ""; table.style.height = ""; table.style.top = ""; table.style.left = ""; table.style.fontSize = ""; elem.style.marginLeft = "55%"; elem.title="Maximize"; elem.width = "15"; elem.height = "15"; elem.src = "https://cdn2.iconfinder.com/data/icons/mixed-vol-7/74/Untitled-1-11-08-07-17-512.png"; maximized = false; } } </script>

var = 'ignore'

将失败。

一些可以通过的选项包括：

if(var == 'Ignore'){print("pass")} else{print("fail")}

还有其他好的选择吗？有没有最佳选择？

我不确定应该如何衡量“最佳”

Answer 1

我们也可以将grepl与ignore.case = T一起使用

var <- "ignore"
if (grepl("Ignore", var, ignore.case = T)) "Pass" else "Fail"
#[1] "Pass"

或将stringr::str_detect与fixed(pattern, ignore_case = T)一起使用

library(stringr)
if (str_detect(var, fixed("Ignore", ignore_case = T))) "Pass" else "Fail"
#[1] "Pass"

如果检查，R不区分大小写

1 个答案: