6.flow_and_control 流程控制

.idea/rust_study.iml

@@ -6,9 +6,13 @@
       <sourceFolder url="file://$MODULE_DIR$/2.hello_cargo/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/3.guessing_game/src" isTestSource="false" />
       <sourceFolder url="file://$MODULE_DIR$/4.variables/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/5.function/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/6.flow_and_control/src" isTestSource="false" />
+      <sourceFolder url="file://$MODULE_DIR$/x.bubble_sort/src" isTestSource="false" />
       <excludeFolder url="file://$MODULE_DIR$/2.hello_cargo/target" />
       <excludeFolder url="file://$MODULE_DIR$/3.guessing_game/target" />
       <excludeFolder url="file://$MODULE_DIR$/4.variables/target" />
+      <excludeFolder url="file://$MODULE_DIR$/target" />
     </content>
     <orderEntry type="inheritedJdk" />
     <orderEntry type="sourceFolder" forTests="false" />

6.flow_and_control/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "flow_and_control"
+edition = "2021"
+version.workspace = true
+
+[dependencies]
+# https://crates.io/search?q=rand
+rand = "0.8.4"

6.flow_and_control/src/main.rs

@@ -0,0 +1,34 @@
+use std::ops::Range;
+
+use rand::Rng;
+
+fn gen_rand_num(rng:Range<i32>) -> impl Fn() -> i32 {
+    let self_rng = rng.clone();
+    // 使用 move 将变量的所有权转移到闭包中
+    move || -> i32 {
+        rand_num(self_rng.clone())
+    }
+}
+
+fn rand_num(rng:Range<i32>) -> i32 {
+    rand::thread_rng().gen_range(rng)
+}
+
+fn main() {
+    // 生成一个闭包，该闭包每次调用时返回一个 -100 到 100 之间的随机数
+    let fn_rand_num = gen_rand_num(-100..100);
+    // 调用闭包，获取随机数
+    let mut num:i32 = fn_rand_num();
+
+    let max_num = rand::thread_rng().gen_range(0..10);
+    let min_num = rand::thread_rng().gen_range(-10..0);
+
+    println!("当随机生成的数 >= {} 且 <= {} 时结束", min_num,max_num);
+    while num < min_num || num > max_num {
+        println!("随机数为: {}", num);
+        num = fn_rand_num();
+    }
+
+    println!("当随机生成的数 >={} 且 <= {}时结束", min_num,max_num);
+    println!("最终的随机数为: {}", num);
+}

Cargo.toml

@@ -17,7 +17,7 @@ members = [
     "2.hello_cargo",
     "3.guessing_game",
     "4.variables",
-    "5.function",
+    "5.function", "6.flow_and_control",
 
     "x.bubble_sort"
 ]