用swift中的单个字符替换字符串中的空格序列

Question

我想用带下划线的字符串替换一系列空格.例如

"This       is     a string with a lot of spaces!"

应该成为

"This_is_a_string_with_a_lot_of_spaces!"

这该怎么做？

Answer 1

替代非正则表达式解决方案:

let foo = "This       is     a string with a lot of spaces!"
let bar = foo
    .componentsSeparatedByString(" ")
    .filter { !$0.isEmpty }
    .joinWithSeparator("_")

print(bar) /* This_is_a_string_with_a_lot_of_spaces! */

也适用于unicode字符(感谢@MartinR这个美丽的例子)

let foo = "       "

// ...

/* _____ */

Answer 2

@remus建议可以简化(并使Unicode/Emoji/Flag-safe)为

let myString = "  This       is     a string with a lot of spaces!         "
let replacement = myString.stringByReplacingOccurrencesOfString("\\s+", withString: "_", options: .RegularExpressionSearch)
print(replacement)
// _This_is_a_string_with_a_lot_of_spaces!____