php7新特性：定义参数和返回值类型

static_test.php

@@ -0,0 +1,40 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: chentao
+ * Date: 2019/1/17
+ * Time: 5:04 PM
+ */
+error_reporting(E_ALL);
+declare(stric_types =0);
+static $c=1;
+$d=3;
+
+$res1 = test(1.5,2);
+echo $res1,"\n";
+$res2 = test(1.5,2);
+echo $res2,"\n";
+
+/*
+ * 输出结果
+ * 7 此时$d=5.5
+ * 8 因为返回值转为int，因此8.5变成了8
+ */
+
+/**
+ * @param int $a 输入参数自动转为int
+ * @param int $b
+ * @return int 返回值自动转为int
+ */
+function test(int $a, int $b) : int {
+    static $d = 4;
+    $res = $a +$b;
+    if (isset($c)) {
+        $res += $c;
+    }
+    if (isset($d)) {
+        $res +=$d;
+        $d += 1.5;
+    }
+    return $res;
+}