diff --git a/src/basic/String.kt b/src/basic/String.kt
new file mode 100644
index 0000000..1722bdb
--- /dev/null
+++ b/src/basic/String.kt
@@ -0,0 +1,69 @@
+package basic
+
+/**
+ * 字符串
+ */
+
+fun main(args: Array<String>) {
+    // String 字符串不可变
+    var a: String = "rainerosion"
+    var b = "raininjury"
+    // 字符串
+    println(a)
+    println(b)
+    // 使用下标取值
+    println(a[0])
+    println(a[1])
+    // 字符串长度
+    println(a.length)
+    /**
+     * 字符串查找
+     */
+    // 首个字符
+    println(a.first())
+    // 末尾字符
+    println(a.last())
+    // get
+    println(a.get(3))
+    println(a[3])
+    // indexOf
+    println(a.indexOf('i'))
+    println(a.lastIndexOf('i'))
+    // 字符串截取
+    println(a.substring(0,4))
+    println(a.substring(0..3))
+    println(a.substring(IntRange(0,4)))
+
+    println(a.subSequence(0..3))
+    println(a.subSequence(IntRange(0,4)))
+    // 字符串替换
+    println(a.replace("erosion",""))
+    println(a.replaceAfter("erosion",""))
+
+    // 字符串分割
+    var c = "rainerosion,rainjury"
+    println(c.split(","))
+
+    // 去除空格
+    var d = "      hello world    "
+    println(d.trim())
+    println(d.trimStart())
+    println(d.trimEnd())
+
+    // 原生字符串
+    var e = """134\r\n\d$"""
+    println(e)
+
+    // 模板表达式
+    var name = "rainerosion"
+    var age = 20
+    var str = "name:$name,age:${age}"
+    println(str)
+    println("${getName()}")
+
+    println("${getName().replace("allms","rainerosion")}")
+}
+
+fun getName(): String{
+    return "allms"
+}
\ No newline at end of file
diff --git a/src/basic/variable.kt b/src/basic/Variable.kt
similarity index 100%
rename from src/basic/variable.kt
rename to src/basic/Variable.kt