How do I trim whitespace from a string in EK9?

← Common String Operations · Ref: Q173

EK9 strings have .trim() for whitespace removal and .trim(char) for removing a specific character.

TRIM WHITESPACE

Remove leading and trailing whitespace:

  cleaned <- myString.trim()

Returns a new string with spaces, tabs, and newlines removed from both ends.

TRIM SPECIFIC CHARACTER

Remove a specific character from both ends:

  unquoted <- myString.trim('"')

Useful for removing surrounding quotes or delimiters.

COMBINE WITH PADDING

Trim is the complement of padding:

  padded <- myString.rightPadded(30)
  trimmed <- padded.trim()

See Q37 for comprehensive string operations. See Q176 for string padding. See Q172 for string case. See Q174 for string concat. See Q175 for string transform.

Example

#!ek9
defines module qa.stringops.trim

  defines program
    StringTrimDemo()
      stdout <- Stdout()

      // === TRIM WHITESPACE ===

      padded <- "  Hello World  "
      trimmed <- padded.trim()
      stdout.println(`Before: [${padded}]`)
      stdout.println(`After trim: [${trimmed}]`)

      // === TRIM SPECIFIC CHARACTER ===

      quoted <- "\"Hello World\""
      unquoted <- quoted.trim('"')
      stdout.println(`Quoted: ${quoted}`)
      stdout.println(`Unquoted: ${unquoted}`)

      dashed <- "---Title---"
      undashed <- dashed.trim('-')
      stdout.println(`Dashed: ${dashed}`)
      stdout.println(`Undashed: ${undashed}`)

      // === COMPLEMENT OF PADDING ===

      original <- "Test"
      rightPad <- original.rightPadded(20)
      stdout.println(`Right padded: [${rightPad}]`)

      backToOriginal <- rightPad.trim()
      stdout.println(`Trimmed back: [${backToOriginal}]`)

Common mistakes

E50060 — String has no strip() method. The correct method name in EK9 is trim(). See ek9 -h E50060 for details.

Incorrect:

trimmed <- padded.strip()

Correct:

trimmed <- padded.trim()

E50060 — String has no trimLeft() method. EK9 provides trim() for both ends and trim(char) for a specific character. Use 'ek9 -h String' to see the full API. See ek9 -h E50060 for details.

Incorrect:

trimmed <- padded.trimLeft()

Correct:

trimmed <- padded.trim()

Coming from another language?

Java: str.trim(), str.strip() (Java 11+). Python: str.strip(), str.strip(chars). Rust: str.trim(), str.trim_matches(char). Go: strings.TrimSpace(), strings.Trim(). JavaScript: str.trim(). Kotlin: str.trim(), str.trim(char). EK9: str.trim(), str.trim(char).

Keywords: clean, leading, spaces, string, strip, text, trailing, trim, whitespace