我如何从字符串变量使用Swift删除最后一个字符?在文档中找不到。
下面是完整的例子:
var expression = "45+22"
expression = expression.substringToIndex(countElements(expression) - 1)
当前回答
全局的dropLast()函数作用于序列，因此也作用于字符串:
var expression = "45+22"
expression = dropLast(expression) // "45+2"
// in Swift 2.0 (according to cromanelli's comment below)
expression = String(expression.characters.dropLast())
其他回答
修剪字符串最后一个字符最简单的方法是:
title = title[title.startIndex ..< title.endIndex.advancedBy(-1)]
全局的dropLast()函数作用于序列，因此也作用于字符串:
var expression = "45+22"
expression = dropLast(expression) // "45+2"
// in Swift 2.0 (according to cromanelli's comment below)
expression = String(expression.characters.dropLast())
使用新的Substring类型用法:
斯威夫特4:
var before: String = "Hello world!"
var lastCharIndex: Int = before.endIndex
var after:String = String(before[..<lastCharIndex])
print(after) // Hello world
短:
var before: String = "Hello world!"
after = String(before[..<before.endIndex])
print(after) // Hello world
let str = "abc"
let substr = str.substringToIndex(str.endIndex.predecessor()) // "ab"
斯威夫特4
var welcome = "Hello World!"
welcome = String(welcome[..<welcome.index(before:welcome.endIndex)])
or
welcome.remove(at: welcome.index(before: welcome.endIndex))
or
welcome = String(welcome.dropLast())
