{
  "name": "substr",
  "type": "function",
  "groups": ["String"],
  "description": "Returns a part of a string.",
  "arguments": [{
    "arg": "string",
    "description": "the full input string"
  }, {
    "arg": "start",
    "description": "integer representing start position to extract beginning with 1; if start is negative, the return string will begin at the end of the string minus the start value"
  }, {
    "arg": "length",
    "optional": true,
    "description": "integer representing length of string to extract; if length is negative, the return string will omit the given length of characters from the end of the string"
  }],
  "examples": [{
    "expression": "substr('HELLO WORLD',3,5)",
    "returns": "'LLO W'"
  }, {
    "expression": "substr('HELLO WORLD',6)",
    "returns": "' WORLD'"
  }, {
    "expression": "substr('HELLO WORLD',-5)",
    "returns": "'WORLD'"
  }, {
    "expression": "substr('HELLO',3,-1)",
    "returns": "'LL'"
  }, {
    "expression": "substr('HELLO WORLD',-5,2)",
    "returns": "'WO'"
  }, {
    "expression": "substr('HELLO WORLD',-5,-1)",
    "returns": "'WORL'"
  }],
  "tags": ["part"]
}