Kotlin 标准函数和静态方法示例详解

val result = with(obj){
	//这里是obj的上下文
	"value" //with 函数的返回值
}

val list = listOf("Apple","Banana","Orange")
val builder = StringBuilder()
builder.append("Start eating fruits\n")
for(fruit in list){
	builder.append(fruit).append("\n")
}
builder.append("Ate all fruits.\n")
val result = builder.toString()
print(result)

		val list = listOf("Apple","Banana","Orange")
        val result = with(StringBuffer()){
            append("Start eating fruit.\n")
            for (fruit in list){
                append(fruit+"\n")
            }
            append("Ate all fruits.\n")
            toString()
        }
        println(result)

val result = obj.run{
	//这里是obj的上下文
	"value"//run函数的返回值
}

val list = listOf("Apple","Banana","Orange")
        val result = StringBuilder().run{
            append("Start eating fruit.\n")
            for (fruit in list){
                append(fruit+"\n")
            }
            append("Ate all fruits.\n")
            toString()
        }
        println(result)

val result = obj.apply{
	//这里是obj的上下文
}
//result == obj

val list = listOf("Apple","Banana","Orange")
        val result = StringBuilder().apply{
            append("Start eating fruit.\n")
            for (fruit in list){
                append(fruit+"\n")
            }
            append("Ate all fruits.\n")
        }
        println(result.toString())

val intent = Intent(this,SecondActivity::class.java).apply { 
	putExtra("param1","data1")
	putExtra("param2","data2")
}
startActivity(intent)

public class Util{
	public static void doAction(){
		System.out.println("do action");
	}
}

Util.doActin();

object Util {
    fun doAction(){
        println("do action")
    }
}

Util.doAction()

class Util {
    fun doAction1(){
        println("do action1")
    }
    companion object{
        fun doAction2(){
            println("do action2")
        }
    } 
}

class Util {
    fun doAction1(){
        println("do action1")
    }
    companion object{
        @JvmStatic
        fun doAction2(){
            println("do action2")
        }
    }
}

fun doSomething(){
    println("do something")
}

classJavaTest {
    public void invokeStaticMethod(){
        HelperKt . doSome thing();
    }
}