at

Return an element from an array.

Usage

var at = require( '@stdlib/array/base/at' );

at( x, index )

Returns an element from an array.

var x = [ 1, 2, 3, 4 ];

var out = at( x, 0 );
// returns 1

out = at( x, 1 );
// returns 2

out = at( x, -2 );
// returns 3

The function accepts the following arguments:

• x: an input array.
• index: element index.

Notes

• If provided an array-like object having an at method, the function defers execution to that method and assumes that the method has the following signature:

  x.at( index )
  

  If provided an array-like object without an at method, the function normalizes a provided index and returns a specified element.

• Negative indices are resolved relative to the last array element, with the last element corresponding to -1.

• If provided out-of-bounds indices, the function always returns undefined.

Examples

var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
var at = require( '@stdlib/array/base/at' );

// Define an array:
var x = discreteUniform( 10, -100, 100 );

// Define an array containing random index values:
var indices = discreteUniform( 100, -x.length, x.length-1 );

// Randomly selected values from the input array:
var i;
for ( i = 0; i < indices.length; i++ ) {
    console.log( 'x[%d] = %d', indices[ i ], at( x, indices[ i ] ) );
}