How can I check if an array index is out of range?

Question

How can I check if an array index is out of range? Or prevent it happening.

Solution 1

int index = 25;
if(index >= 0 && index < array.Length)
{
    //it exists
}

Source: Does Index of Array Exist

Solution 2

Another way of checking if an array is out of bounds is to make a function. This will check if the index is "in bounds". If the index is below zero or over the array length you will get the result false.

private bool inBounds (int index, int[] array) 
{
    return (index >= 0) && (index < array.Length);
}

Solution 3

Correct way would be

int index = 25;
if (index >= 0 && index < array.Length)
{}

Comments

[Mr.Bigglesworth]

Typo there array.Length not array.Legth (being picky)

[Brandon Kramer]

Length is misspelled.

[dcg]

Fixed right now. Thanks.

[RandomGuy]

<3 Thanks, thats it, but i have to check on multiple arrays at the sametime, and if it is right according to the DB. But i figured it out. Thanks anyway. Take Care!

[Serlite]

For future reference, if you find another question that you believe has the exact answer, don't duplicate that answer into your own answer. Instead, click the "flag" option under a question, choose "Flag to close > Duplicate question", and choose the appropriate question.

[Jamshaid K.]

it will fail when someone passes any value less than 0. so need an additional check as index >= 0 which combines the if statement to become if(index >= 0 && index < array.Length){}

[matt]

This should be built in as a member function of the array class..

[moto_geek]

typo.. s/b Length (uppercase)