Trying to determine if an array holds a specific value? (I've experimented with a few methods, but I'm not quite sure yet)

Question

Trying to determine if an array holds a specific value? (I've experimented with a few methods, but I'm not quite sure yet)

Being relatively new to JavaScript (I've been studying for about a week), I am facing a challenge in figuring out how to determine if an array contains a specific string. Here, you can find the word-guessing game that I created.

The 'contains' function is defined like this:

function contains(word, list){
  if(word in list){
    return true;
  }
  else {
    return false;
  }
};

Despite my efforts, I always end up with a false value and I'm not sure what I'm missing.

I attempted to implement both the third technique mentioned here and the recommended technique illustrated here, but encountered the same issue.

If anyone could provide some assistance, it would be greatly appreciated!

javascript arrays

Answer 1

Answer №1

In order to clarify, a separate answer is being provided here. The proper method to check if an element is in an array:

var myArr = ['oranges', 'grapes', 'kiwis'];

if (myArr.indexOf('kiwis') > -1) { // myArr.indexOf('kiwis') will return 2
    console.log('we have kiwis'); // this will be displayed
}

if (myArr.indexOf('watermelon') > -1) { // since it's not in the array, it will be -1
    console.log('no watermelon!'); // this will not display
}

It's worth mentioning that for...in loop is not suited for iterating over arrays as it is primarily used to iterate over object keys. When it comes to iterating over arrays in JavaScript, using a traditional for loop is the recommended approach.

Answer 2

In order to clarify, a separate answer is being provided here. The proper method to check if an element is in an array:

var myArr = ['oranges', 'grapes', 'kiwis'];

if (myArr.indexOf('kiwis') > -1) { // myArr.indexOf('kiwis') will return 2
    console.log('we have kiwis'); // this will be displayed
}

if (myArr.indexOf('watermelon') > -1) { // since it's not in the array, it will be -1
    console.log('no watermelon!'); // this will not display
}

It's worth mentioning that for...in loop is not suited for iterating over arrays as it is primarily used to iterate over object keys. When it comes to iterating over arrays in JavaScript, using a traditional for loop is the recommended approach.

Answer 3

Answer №2

To determine the index of a particular element in an array, you can utilize the indexOf method.
Keep in mind that the in operator is used to check for keys, not values within objects.
Alternatively, you can iterate through all object keys using a for..in loop:

for (key in object)
    console.log(object[key])

In the context of arrays, a similar outcome could be achieved with the following approach:

for (index=0; index<array.length; index++)
    console.log(array[i])

Answer 4

To determine the index of a particular element in an array, you can utilize the indexOf method.
Keep in mind that the in operator is used to check for keys, not values within objects.
Alternatively, you can iterate through all object keys using a for..in loop:

for (key in object)
    console.log(object[key])

In the context of arrays, a similar outcome could be achieved with the following approach:

for (index=0; index<array.length; index++)
    console.log(array[i])

Trying to determine if an array holds a specific value? (I've experimented with a few methods, but I'm not quite sure yet)

Answer №1

Answer №2

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