Concatenate strings

Supported in: Batch, Streaming

Concatenates a list of strings with the specified separator.

Expression categories: String

Declared arguments

• Expressions - List of strings to be concatenated.
  List<Expression<String>>
• optional Null output if any input is null - If any of the input values are null, then the output should be null. If false, null values in the input are ignored.
  Literal<Boolean>
• optional Separator - Separator to be added between the strings.
  Literal<String>

Output type: String

Examples

Example 1: Base case

Argument values:

• Expressions: [hello, world]
• Null output if any input is null: null
• Separator: _

Output: hello_world

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Example 2: Null case

Argument values:

• Expressions: [hello, null, world, !]
• Null output if any input is null: null
• Separator: --

Output: hello--world--!

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Example 3: Null case

Argument values:

• Expressions: [hello, null, world, !]
• Null output if any input is null: true
• Separator: --

Output: null

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