Method .includes() is not a function error

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0
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I am studying through Eloquent Javascript, and I have the following code as one of the exercices.

class Group 
constructor()
 this.arr = 


add(value)
 if(!this.has(value)) 
 this.arr = this.arr.push(value)
 


has(value)
 return this.arr.includes(value);


delete(value)
 this.arr = this.arr.filter(n => n !== value)


static from(collection)
 let rec = new Group;
 for (let value of collection)
 rec.add(value)
 
return rec

It seems right and it should be working but I get the error

TypeError: arr.includes is not a function

What is that about? I can't find the answer.

asked Nov 10 at 18:27

Zhast

Try to change your "has" method to an array function
– Steve Nosse
Nov 10 at 18:29

3

Which browser/version of JS are you using? See e.g. developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… for compatibility
– jonrsharpe
Nov 10 at 18:29

add a comment |

up vote
0
down vote

favorite

I am studying through Eloquent Javascript, and I have the following code as one of the exercices.

class Group 
constructor()
 this.arr = 


add(value)
 if(!this.has(value)) 
 this.arr = this.arr.push(value)
 


has(value)
 return this.arr.includes(value);


delete(value)
 this.arr = this.arr.filter(n => n !== value)


static from(collection)
 let rec = new Group;
 for (let value of collection)
 rec.add(value)
 
return rec

It seems right and it should be working but I get the error

TypeError: arr.includes is not a function

What is that about? I can't find the answer.

asked Nov 10 at 18:27

Zhast

Try to change your "has" method to an array function
– Steve Nosse
Nov 10 at 18:29

3

Which browser/version of JS are you using? See e.g. developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… for compatibility
– jonrsharpe
Nov 10 at 18:29

add a comment |

up vote
0
down vote

favorite

I am studying through Eloquent Javascript, and I have the following code as one of the exercices.

class Group 
constructor()
 this.arr = 


add(value)
 if(!this.has(value)) 
 this.arr = this.arr.push(value)
 


has(value)
 return this.arr.includes(value);


delete(value)
 this.arr = this.arr.filter(n => n !== value)


static from(collection)
 let rec = new Group;
 for (let value of collection)
 rec.add(value)
 
return rec

It seems right and it should be working but I get the error

TypeError: arr.includes is not a function

What is that about? I can't find the answer.

asked Nov 10 at 18:27

Zhast

I am studying through Eloquent Javascript, and I have the following code as one of the exercices.

class Group 
constructor()
 this.arr = 


add(value)
 if(!this.has(value)) 
 this.arr = this.arr.push(value)
 


has(value)
 return this.arr.includes(value);


delete(value)
 this.arr = this.arr.filter(n => n !== value)


static from(collection)
 let rec = new Group;
 for (let value of collection)
 rec.add(value)
 
return rec

It seems right and it should be working but I get the error

TypeError: arr.includes is not a function

What is that about? I can't find the answer.

javascript function methods include typeerror

asked Nov 10 at 18:27

Zhast

asked Nov 10 at 18:27

Zhast

asked Nov 10 at 18:27

Zhast

asked Nov 10 at 18:27

Zhast

asked Nov 10 at 18:27

Zhast

Try to change your "has" method to an array function
– Steve Nosse
Nov 10 at 18:29

3

Which browser/version of JS are you using? See e.g. developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… for compatibility
– jonrsharpe
Nov 10 at 18:29

add a comment |

Try to change your "has" method to an array function
– Steve Nosse
Nov 10 at 18:29

3

Which browser/version of JS are you using? See e.g. developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… for compatibility
– jonrsharpe
Nov 10 at 18:29

Try to change your "has" method to an array function
– Steve Nosse
Nov 10 at 18:29

Which browser/version of JS are you using? See e.g. developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… for compatibility
– jonrsharpe
Nov 10 at 18:29

add a comment |

1 Answer
1

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oldest

votes

up vote
1
down vote

From docs,

The push() method adds one or more elements to the end of an array and
returns the new length of the array.

Hence, the problem is with this line. this.arr is no longer an array after this line.

this.arr = this.arr.push(value)

So, update this to following

this.arr.push(value)

edited Nov 10 at 18:42

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

1

Thank you, the arr variable became a number, of course!!
– Zhast
Nov 10 at 18:36

@Zhast - Glad to help you!
– Nikhil Aggarwal
Nov 10 at 18:36

add a comment |

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1 Answer
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1 Answer
1

active

oldest

votes

up vote
1
down vote

From docs,

The push() method adds one or more elements to the end of an array and
returns the new length of the array.

Hence, the problem is with this line. this.arr is no longer an array after this line.

this.arr = this.arr.push(value)

So, update this to following

this.arr.push(value)

edited Nov 10 at 18:42

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

1

Thank you, the arr variable became a number, of course!!
– Zhast
Nov 10 at 18:36

@Zhast - Glad to help you!
– Nikhil Aggarwal
Nov 10 at 18:36

add a comment |

up vote
1
down vote

From docs,

The push() method adds one or more elements to the end of an array and
returns the new length of the array.

Hence, the problem is with this line. this.arr is no longer an array after this line.

this.arr = this.arr.push(value)

So, update this to following

this.arr.push(value)

edited Nov 10 at 18:42

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

1

Thank you, the arr variable became a number, of course!!
– Zhast
Nov 10 at 18:36

@Zhast - Glad to help you!
– Nikhil Aggarwal
Nov 10 at 18:36

add a comment |

up vote
1
down vote

From docs,

The push() method adds one or more elements to the end of an array and
returns the new length of the array.

Hence, the problem is with this line. this.arr is no longer an array after this line.

this.arr = this.arr.push(value)

So, update this to following

this.arr.push(value)

edited Nov 10 at 18:42

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

From docs,

The push() method adds one or more elements to the end of an array and
returns the new length of the array.

Hence, the problem is with this line. this.arr is no longer an array after this line.

this.arr = this.arr.push(value)

So, update this to following

this.arr.push(value)

edited Nov 10 at 18:42

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

edited Nov 10 at 18:42

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

answered Nov 10 at 18:29

Nikhil Aggarwal

23.1k32647

1

Thank you, the arr variable became a number, of course!!
– Zhast
Nov 10 at 18:36

@Zhast - Glad to help you!
– Nikhil Aggarwal
Nov 10 at 18:36

add a comment |

1

Thank you, the arr variable became a number, of course!!
– Zhast
Nov 10 at 18:36

@Zhast - Glad to help you!
– Nikhil Aggarwal
Nov 10 at 18:36

Thank you, the arr variable became a number, of course!!
– Zhast
Nov 10 at 18:36

@Zhast - Glad to help you!
– Nikhil Aggarwal
Nov 10 at 18:36

add a comment |

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