13.for和foreach循环

fun main(args: Array<String>) {
    var str = "abcd"
    /*-----------------------for循环---------------*/
    for (a in str) {
        println(a)
    }
    for ((index, c) in str.withIndex()) {
        println("index=$index   value=$c")
    }
    /*-----------------------高级for循环---------------*/
    str.forEach { println(it) }

    //打印角标
    str.forEachIndexed{index, c -> println("index=$index   value=$c") }
}

输出结果: