println("我被调用了") return if (isNotEmpty() && this[0].isLowerCase()) substring(0, 1).toUpperCase() + substring(1) else "String is null" } 1. 2. 3. 4. 5. 6. 7. 8. 9. 安全操作符“let” 安全调用允许我们使用可空类型值调用函数,但是我们还想做点额外的事情,比如变量为空白字符...
但是会报错:Smart cast to 'String' is impossible, beacuase 'test' is a mutable property that could have been changed by this time sNullOrEmpty | isNullOrBlank publicinlinefunCharSequence?.isNullOrEmpty():Boolean=this==null||this.length ==0publicinlinefunCharSequence?.isNullOrBlank():Boolean=...
本文摘自:http://blog.farifam.com/2018/01/28/kotlin-charsequence-isnullorblank-vs-isnullorempty/ IsNullOrBlank() 和 IsNullOrEmpty()這兩者有什麼不一樣呢?請往下看 Koltin provide two options to check if a CharSequence or String have a null or empty value, IsNullOrBlank & isNullOrEmpty. What...
本文摘自:http://blog.farifam.com/2018/01/28/kotlin-charsequence-isnullorblank-vs-isnullorempty/ Koltin provide two options to check if a CharSequence or String have a null or empty value, IsNullOrBlank & isNullOrEmpty. What’s the difference? let’s check it by code: var data: String?
openclassDeclarationProcessor{……}object EmptyDeclarationProcessor:DeclarationProcessor(){……} 函数名 函数、属性与局部变量的名称以小写字母开头、使用驼峰而不使用下划线: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 funprocessDeclarations(){……}vardeclarationCount=…… ...
object EmptyDeclarationProcessor : DeclarationProcessor() { …… } 1. 2. 3. 函数名 函数、属性与局部变量的名称以小写字母开头、使用驼峰而不使用下划线: fun processDeclarations() { …… } var declarationCount = …… 1. 2. 例外:用于创建类实例的工厂函数可以与要创建的类具有相同的名称: ...
isNullEmptyOrBlank(): Boolean { return this == null || this.isEmpty() || this.isBlank() } fun main() { val text: String? = "Hello" val emptyText: String? = "" val blankText: String? = " " println(text.isNullEmptyOrBlank()) // false println(emptyText.isNullEmptyOrBlank()...
How to break out of a while loop if a blank line or null is entered? Solution 1: Simplest way is probably just while(true) { val input = readLine() if (input.isNullOrEmpty()) break // or isNullOrBlank (includes empty whitespace) ...
First up, let us create a blank Spring project. We will do this with the Spring Initializr plugin we just installed: PressCTRL + SHIFT + Pto open the command palette SelectSpring Initialzr: Create a Gradle project... Select version (I recommend3.3.4) ...
总结:" "blank space isBlank=trueisEmpty=false