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$jsonArrayShift

$jsonArrayShift removes the first element from a JSON array and returns it.

Syntax

$jsonArrayShift[Key;...]

• Key: one or more keys forming the path to the array.

What happens

1. $jsonParse loads the JSON object.
2. $jsonArrayShift removes the first element from the array and returns its value.
3. All remaining elements shift down by one position.

Example 1: Shift the first element

$nomention
$jsonParse[{"music":["Paranoid","Ping! 2","Tokyo"\]}]
Removed: $jsonArrayShift[music]
Remaining: $jsonJoinArray[music;, ]

What happens:

1. $jsonParse loads the object.
2. $jsonArrayShift[music] removes Paranoid from the front and returns it.
3. $jsonJoinArray shows what is left.

Output:

Removed: Paranoid
Remaining: Ping! 2, Tokyo

Example 2: Shift until empty

$nomention
$jsonParse[{"queue":["first","second","third"\]}]
> $jsonArrayShift[queue]
> $jsonArrayShift[queue]
Remaining: $jsonJoinArray[queue;, ]

What happens:

1. $jsonParse loads the object.
2. The first $jsonArrayShift removes and returns first.
3. The second removes and returns second.
4. $jsonJoinArray shows what is left.

Output:

> first
> second
Remaining: third

Common uses

• Queue systems: process items in order from the front (FIFO)
• Consuming lists: work through a list from the beginning
• Removing old entries: drop the oldest item from a history array

See also

• $jsonArrayPop: to remove the last element instead
• $jsonArrayUnshift: to add an element to the front
• $jsonJoinArray: to display the remaining array after shifting