expressions,contexts,failure step

 expressions:

objects,function calls,arithmetic operations,etc

${{ }}

${{toJson(runner)}} #job,github

contexts available: runner,job,github,steps,etc

echo ${{contains('hello','ll')}}

echo ${{format('Hello {0} {1}','World','!')}}

similarly startsWith,endsWith,etc

log-env:

    runs-on: ubuntu-latest

    if: github.event_name == 'push'

    steps:

if can also be used in individual steps.

-name: spomefd

 if: failure() #always()

 run: echo "$STEPS_CONTEXT"