Merge pull request #4 from tainguyenbp/feat/learn-programming-rust-lang03

test pointer and closures

Author: tainguyenbp

rust-basic/functions/closures/closures01

@@ -0,0 +1,8 @@
+fn main() {
+    let x = 4;
+    println!("{}", get_square_value(x));
+}
+
+fn get_square_value(i: i32) -> i32 {
+    i * i
+}

rust-basic/functions/closures/closures01.rs

@@ -0,0 +1,7 @@
+fn main() {
+    let x = 65536;
+    let square = |i: i32| -> i32 { // Input parameters are passed inside | | and expression body is wrapped within { }
+        i * i
+    };
+    println!("{}", square(x));
+}

rust-basic/functions/closures/closures02

@@ -0,0 +1,5 @@
+fn main() {
+    let x = 40;
+    let square = |i| i * i; // { } are optional for single-lined closures
+    println!("{}", square(x));
+}

rust-basic/functions/closures/closures02.rs

@@ -0,0 +1,5 @@
+fn main() {
+    let x = 300;
+    let x_square = |i: i32| -> i32 { i * i }(x); // { } are mandatory while creating and calling same time.
+    println!("{}", x_square);
+}

rust-basic/functions/closures/closures03

@@ -0,0 +1,5 @@
+fn main() {
+    let x = 68;
+    let x_square = |i| -> i32 { i * i }(x); // ⭐️ The return type is mandatory.
+    println!("{}", x_square);
+}

rust-basic/functions/closures/closures03.rs

@@ -0,0 +1,15 @@
+
+
+fn main() {
+    // 01. Without type declarations.
+    let p1 = plus_one;
+    let x = p1(9); // 6
+
+    println!("Result: {}", x);
+
+}
+
+
+fn plus_one(a: i32) -> i32 {
+    a + 1
+}

rust-basic/functions/closures/closures04

@@ -0,0 +1,11 @@
+fn main() {
+    // 02. With type declarations.
+    let p1: fn(i32) -> i32 = plus_one;
+    let x = p1(7); 
+
+    println!("Result: {}", x);
+}
+
+fn plus_one(a: i32) -> i32 {
+    a + 1
+}