Question

尝试解决我需要在35°C和35°C之间打印随机温度值的练习。每5秒-10°C，然后是日期和时间。一切看起来都按预期工作，但是当我在测试脚本中输入代码时，我会遇到以下错误。

implicit declaration of functions errors 这是我的代码：

<!DOCTYPE html>
<html >
  <head>
    <meta charset="UTF-8">
    <title>Persistent Scrollbar</title>
    <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700,400italic">

    <link rel='stylesheet prefetch' href='https://cdn.gitcdn.xyz/cdn/angular/bower-material/v1.0.5/angular-material.css'>
    <link rel='stylesheet prefetch' href='https://material.angularjs.org/1.0.5/docs.css'>
    <script>
    angular
  .module('MyApp',['ngMaterial', 'ngMessages', 'material.svgAssetsCache'])
  .controller('DemoCtrl', function($scope) {
    $scope.user = {
      state: 'CA'
    };

    $scope.states = ('AL AK AZ AR CA CO CT DE FL GA HI ID IL IN IA KS KY LA ME MD MA MI MN MS ' +
    'MO MT NE NV NH NJ NM NY NC ND OH OK OR PA RI SC SD TN TX UT VT VA WA WV WI ' +
    'WY').split(' ').map(function(state) {
        return {abbrev: state};
      })
  })

    </script>

  </head>

  <body>

  <div ng-controller="DemoCtrl" layout="column" ng-cloak="" class="md-inline-form inputdemoBasicUsage" ng-app="MyApp">

  <md-content layout-padding="">
    <div>
      <form name="userForm">
        <div layout-gt-sm="row">

          <md-input-container class="md-block" flex-gt-sm="">
            <label>State</label>
            <md-select ng-model="user.state">
              <md-option ng-repeat="state in states" value="{{state.abbrev}}">
                {{state.abbrev}}
              </md-option>
            </md-select>
          </md-input-container>

        </div>

      </form>
    </div>
  </md-content>

</div>

<script src='https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular.js'></script>
<script src='https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular-animate.min.js'></script>
<script src='https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular-route.min.js'></script>
<script src='https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular-aria.min.js'></script>
<script src='https://ajax.googleapis.com/ajax/libs/angularjs/1.4.8/angular-messages.min.js'></script>
<script src='http://ngmaterial.assets.s3.amazonaws.com/svg-assets-cache.js'></script>
<script src='https://cdn.gitcdn.xyz/cdn/angular/bower-material/v1.0.5/angular-material.js'></script>

  </body>
</html>

这些是我的结果：

These are my results

这是测试脚本检查的内容：

This is what the test script checks for

由于我无法看到自己的错误，所以非常感谢任何帮助。

Answer 1

你未能#include <stdlib.h>。因此，您调用的函数被假定为接受未知数量的参数并返回类型int的值。这会导致未定义的行为。

将#include <stdlib.h>放在文件的顶部。

Answer 2

我有类似的问题。我的代码已编译，但收到警告消息。

// Selection sort

#include <stdio.h>
#include <math.h>

int main()
{
    int list[100], i;

    for(i = 0 ; i < 100; i++) {
        list[i] = ( rand()%99 + 1 );
        printf("%d ", list[i]);
    } printf("\n");

    return 0;
}

编译时，

gcc -o selection_sort selection_sort.c -lm
selection_sort.c: In function ‘main’:
selection_sort.c:11:15: warning: implicit declaration of function ‘rand’; did you mean ‘nanl’? [-Wimplicit-function-declaration]
list[i] = ( rand()%99 + 1 );
           ^~~~
           nanl

添加<stdlib.h>后警告消息消失了。

函数srand，rand和system的隐式声明

2 个答案: