我怎么能在多行分割字符串,如下面?
var text:String = "This is some text
over multiple lines"
我怎么能在多行分割字符串,如下面?
var text:String = "This is some text
over multiple lines"
当前回答
下面是一个代码片段,用n个字符分隔字符串:
//: A UIKit based Playground for presenting user interface
import UIKit
import PlaygroundSupport
class MyViewController : UIViewController {
override func loadView() {
let str = String(charsPerLine: 5, "Hello World!")
print(str) // "Hello\n Worl\nd!\n"
}
}
extension String {
init(charsPerLine:Int, _ str:String){
self = ""
var idx = 0
for char in str {
self += "\(char)"
idx = idx + 1
if idx == charsPerLine {
self += "\n"
idx = 0
}
}
}
}
其他回答
下面的例子描述了一个多行连续,使用圆括号作为一个简单的解决方法,以解决Xcode 6.2 Beta版本的Swift错误,它抱怨表达式太复杂,无法在合理的时间内解析,并考虑将其分解为更小的片段:
.
.
.
return String(format:"\n" +
(" part1: %d\n" +
" part2: %d\n" +
" part3: \"%@\"\n" +
" part4: \"%@\"\n" +
" part5: \"%@\"\n" +
" part6: \"%@\"\n") +
(" part7: \"%@\"\n" +
" part8: \"%@\"\n" +
" part9: \"%@\"\n" +
" part10: \"%@\"\n" +
" part12: \"%@\"\n") +
" part13: %f\n" +
" part14: %f\n\n",
part1, part2, part3, part4, part5, part6, part7, part8,
part9, part10, part11, part12, part13, part14)
.
.
.
正如litso所指出的,在一个表达式中重复使用+-操作符会导致Xcode Beta挂起(刚刚用Xcode 6 Beta 5检查过):Xcode 6 Beta无法编译
目前,多行字符串的另一种替代方法是使用一个字符串数组,并将其压缩为+:
var text = ["This is some text ",
"over multiple lines"].reduce("", +)
或者,可以更简单地使用join:
var text = "".join(["This is some text ",
"over multiple lines"])
样本
var yourString = "first line \n second line \n third line"
以防您发现+运算符不合适
从Swift 4.0开始,可以使用多行字符串,但有一些规则:
你需要用三个双引号"""来开始和结束字符串。 你的字符串内容应该从它自己的行开始。 结尾的"""也应该在自己的行上开始。
除此之外,你就可以开始了!这里有一个例子:
let longString = """
When you write a string that spans multiple
lines make sure you start its content on a
line all of its own, and end it with three
quotes also on a line of their own.
Multi-line strings also let you write "quote marks"
freely inside your strings, which is great!
"""
查看Swift 4的新功能以获得更多信息。
迅速:
@connor是正确答案,但如果你想在打印语句中添加行,你要寻找的是\n和/或\r,这些被称为转义序列或转义字符,这是一个关于该主题的Apple文档链接。
例子:
print("First line\nSecond Line\rThirdLine...")