Grunt reference error - node.js

Question

Gruntfile.js
module.exports = functions(grunt)
{
grunt.initConfig({
//pkg: grunt.file.readJSON('package.json'),
concat: {
options: {
separator: ';',
},
dist: {
src: ['APIdocu/AccountsCollection.md', 'APIdocu/AccountsFollowersCollection.md'],
dest: 'APIdocu/ConcatApis.md',
//files: {
//'APIdocu/NewApi.md' : ['APIdocu/AccountsCollection.md', 'APIdocu/AccountsFollowersCollection.md']
},
},
});
grunt.loadNpmTasks('grunt-contrib-concat');
//tasks
grunt.registerTask('default', ["concat"]);
}
error message
Initializing
Command-line options: --verbose
Reading "Gruntfile.js" Gruntfile...OK
Registering Gruntfile tasks.
Loading "Gruntfile.js" tasks...ERROR
ReferenceError: grunt is not defined
at Object.<anonymous> (C:\Users\gs1460\Desktop\Markdownfiles\apis\Gruntfile.js:1:90)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:364:17)
at require (module.js:380:17)
at loadTask (C:\Users\gs1460Desktop\Markdownfiles\apis\node_modules\grunt\lib\grunt\task.js:323:10)
at Task.task.init (C:\Users\gs1460\Desktop\Markdownfiles\apis\node_modules\grunt\lib\grunt\task.js:437:5)
at Object.grunt.tasks (C:\Users\gs1460\Desktop\Markdownfiles\apis\node_modules\grunt\lib\grunt.js:120:8)
at Object.module.exports [as cli] (C:\Users\gs1460\Desktop\Markdownfiles\apis\node_modules\grunt\lib\grunt\cli.js:38:9)
Running tasks: concat:dist
Warning: Task "concat:dist" not found. Use --force to continue.
Aborted due to warnings.
How do I get rid of this error.
I need to concatenate md files to one.It gives me the above error. Tried changing the code many times. But same issue. Can you help in this.

Answer 1

Probably the problem is that you are writting functions instead of function.
Check also if the variable grunt is in the correct scope. And please use tabs correctly!
module.exports = function(grunt)
Regards.