# Reverse array elements in Julia – reverse(), reverse!() and reverseind() Methods

The `reverse()` is an inbuilt function in julia which is used to reverse the specified vector v from start to stop.

Syntax:
reverse(v, start, stop)
or
reverse(A; dims::Integer)

Parameters:

• v: Specified vector.
• start: Specified starting value.
• stop: Specified stopping value.
• A: Specified array.
• dims::Integer: Specified dimensions.

Returns: It returns a reversed copy of the vector.

Example 1:

 `# Julia program to illustrate  ` `# the use of reverse() method ` `  `  `# Getting the reversed copy of  ` `# the specified vector. ` `A ``=` `Vector(``2``:``8``) ` `println(reverse(A)) ` `println(reverse(A, ``3``, ``6``)) ` `println(reverse(A, ``7``, ``4``)) `

Output:

```[8, 7, 6, 5, 4, 3, 2]
[2, 3, 7, 6, 5, 4, 8]
[2, 3, 4, 5, 6, 7, 8]```

Example 2:

 `# Julia program to illustrate  ` `# the use of reverse() method ` `  `  `# Getting reversed array in  ` `# the specified dimension ` `A ``=` `[``5` `10``; ``15` `20``] ` `println(reverse(A, dims ``=` `1``)) ` `println(reverse(A, dims ``=` `2``)) `

Output:

#### reverse!()

The `reverse!()` is an inbuilt function in julia which is In-place version of reverse() function.

Syntax:
reverse!(v, start, stop)

Parameters:

• v: Specified vector.
• start: Specified starting value.
• stop: Specified stopping value.

Returns: It returns a reversed copy of the vector.

Example:

 `# Julia program to illustrate  ` `# the use of reverse !() method ` `  `  `# Getting the reversed copy of  ` `# the specified vector. ` `A ``=` `Vector(``2``:``8``) ` `println(reverse !(A)) ` `println(reverse !(A, ``3``, ``6``)) `

Output:

```[8, 7, 6, 5, 4, 3, 2]
[8, 7, 3, 4, 5, 6, 2]
```

#### reverseind

The `reverseind()` is an inbuilt function in julia which is used to return the corresponding index in v so that v[reverseind(v, i)] == reverse(v)[i], where i is the given index.

Syntax:
reverseind(v, i)

Parameters:

• v: Specified string.
• i: Specified index.

Returns: It returns the corresponding index in v so that v[reverseind(v, i)] == reverse(v)[i].

Example:

 `# Julia program to illustrate  ` `# the use of reverseind() method ` `  `  `# Getting the corresponding index in v ` `# so that v[reverseind(v, i)] == reverse(v)[i] ` `V ``=` `reverse(``"Geeks"``) ` `for` `i ``in` `1``:length(r) ` `    ``print``(V[reverseind(``"Geeks"``, i)]) ` `end `

Output:

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