jq · lesson 8 of 32 · Filtering & conditions

select & comparisons

select(condition) lets a value through only when the condition is true — it is jq's way to filter.

Example 1Members older than 30

Document

{
  "team": "Platform",
  "office": { "city": "Berlin", "floor": 3 },
  "members": [
    { "name": "Ada", "age": 36, "role": "lead", "active": true,
      "email": "[email protected]", "skills": ["rust", "sql"] },
    { "name": "Linus", "age": 28, "role": "dev", "active": true,
      "email": null, "skills": ["c", "shell"] },
    { "name": "Grace", "age": 45, "role": "dev", "active": false,
      "skills": ["cobol"] },
    { "name": "Alan", "age": 41, "role": "qa", "active": true,
      "email": "[email protected]", "skills": [] }
  ]
}

Query

.members[] | select(.age > 30) | .name

.members[] Stream the members.
select(.age > 30) Pass a member on only when the condition is true. Inside it, . is that one member.
| .name Read the name of those that passed.

Result

"Ada"
"Grace"
"Alan"

Try it in the playground

Good to know

Comparison operators: ==, !=, <, <=, >, >=. Strings compare too: select(.role == "dev").