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Add

Add behaves differently according to the type of the LHS:
arrays: concatenate
number scalars: arithmetic addition
string scalars: concatenate
maps: shallow merge (use the multiply operator (*) to deeply merge)
Use += as a relative append assign for things like increment. Note that .a += .x is equivalent to running .a = .a + .x.
Concatenate arrays
Given a sample.yml file of:
a:
  - 1
  - 2
b:
  - 3
  - 4
then
yq '.a + .b' sample.yml
will output
- 1
- 2
- 3
- 4
Concatenate to existing array
Note that the styling of a is kept.
Given a sample.yml file of:
a: [1,2]
b:
  - 3
  - 4
then
yq '.a += .b' sample.yml
will output
a: [1, 2, 3, 4]
b:
  - 3
  - 4
Concatenate null to array
Given a sample.yml file of:
a:
  - 1
  - 2
then
yq '.a + null' sample.yml
will output
- 1
- 2
Append to existing array
Note that the styling is copied from existing array elements
Given a sample.yml file of:
a: ['dog']
then
yq '.a += "cat"' sample.yml
will output
a: ['dog', 'cat']
Prepend to existing array
Given a sample.yml file of:
a:
  - dog
then
yq '.a = ["cat"] + .a' sample.yml
will output
a:
  - cat
  - dog
Add new object to array
Given a sample.yml file of:
a:
  - dog: woof
then
yq '.a + {"cat": "meow"}' sample.yml
will output
- dog: woof
- cat: meow
Relative append
Given a sample.yml file of:
a:
  a1:
    b:
      - cat
  a2:
    b:
      - dog
  a3: {}
then
yq '.a[].b += ["mouse"]' sample.yml
will output
a:
  a1:
    b:
      - cat
      - mouse
  a2:
    b:
      - dog
      - mouse
  a3:
    b:
      - mouse
String concatenation
Given a sample.yml file of:
a: cat
b: meow
then
yq '.a += .b' sample.yml
will output
a: catmeow
b: meow
Number addition - float
If the lhs or rhs are floats then the expression will be calculated with floats.
Given a sample.yml file of:
a: 3
b: 4.9
then
yq '.a = .a + .b' sample.yml
will output
a: 7.9
b: 4.9
Number addition - int
If both the lhs and rhs are ints then the expression will be calculated with ints.
Given a sample.yml file of:
a: 3
b: 4
then
yq '.a = .a + .b' sample.yml
will output
a: 7
b: 4
Increment numbers
Given a sample.yml file of:
a: 3
b: 5
then
yq '.[] += 1' sample.yml
will output
a: 4
b: 6
Date addition
You can add durations to dates. Assumes RFC3339 date time format, see date-time operators for more information.
Given a sample.yml file of:
a: 2021-01-01T00:00:00Z
then
yq '.a += "3h10m"' sample.yml
will output
a: 2021-01-01T03:10:00Z
Date addition - custom format
You can add durations to dates. See date-time operators for more information.
Given a sample.yml file of:
a: Saturday, 15-Dec-01 at 2:59AM GMT
then
yq 'with_dtf("Monday, 02-Jan-06 at 3:04PM MST", .a += "3h1m")' sample.yml
will output
a: Saturday, 15-Dec-01 at 6:00AM GMT
Add to null
Adding to null simply returns the rhs
Running
yq --null-input 'null + "cat"'
will output
cat
Add maps to shallow merge
Adding objects together shallow merges them. Use * to deeply merge.
Given a sample.yml file of:
a:
  thing:
    name: Astuff
    value: x
  a1: cool
b:
  thing:
    name: Bstuff
    legs: 3
  b1: neat
then
yq '.a += .b' sample.yml
will output
a:
  thing:
    name: Bstuff
    legs: 3
  a1: cool
  b1: neat
b:
  thing:
    name: Bstuff
    legs: 3
  b1: neat
Custom types: that are really strings
When custom tags are encountered, yq will try to decode the underlying type.
Given a sample.yml file of:
a: !horse cat
b: !goat _meow
then
yq '.a += .b' sample.yml
will output
a: !horse cat_meow
b: !goat _meow
Custom types: that are really numbers
When custom tags are encountered, yq will try to decode the underlying type.
Given a sample.yml file of:
a: !horse 1.2
b: !goat 2.3
then
yq '.a += .b' sample.yml
will output
a: !horse 3.5
b: !goat 2.3

Operators

Alternative (Default value)

Last modified 10mo ago