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Template:Evaldemo/3 [ talk edit history links ] shows the call of a template or predefined template and its result, for documentation.

{{Evaldemo/3|left side|up to 6 additional parameters}}
{{Evaldemo/3|left side|up to 6 additional parameters|s=separator}}
The default separator is "gives", use s== to get "=". The first parameter has to be specified and can't be empty, compare template:Evaldemo (edittalklinkshistory). Please note that for parser functions the first parameter belongs to the left side before the "|" vertical bar aka pipe, use {{evaldemo}} for examples without any vertical bar.
  1. {{Evaldemo/3|#expr:5*7|s==}}
    {{#expr:5*7}} = 35
  2. {{Evaldemo/3|#ifeq:1.00|+1|okay|bad}}
    {{#ifeq:1.00|+1|okay|bad}} gives okay
  3. {{Evaldemo/3|#ifeq:this|that|true|s=is}}
    {{#ifeq:this|that|true|false}} is false

Optional substitution with subst=subst: is not supported. It's anyway against the spirit of this demo template showing what another template actually does, and not what it did some time ago.