CODEWITHSUNDEEP
clualua-tablelua-api
Victor Martins
Victor Martins

Reputation: 769

Getting array value from index using Lua C Api

I have this array:

a = {{4,2,2,6}, {2,1,1,2}}

How can I retrieve an index from that array to a C program?

For example:

a[1] -- {4,2,2,6}
a[1][2] -- 2

Upvotes: 3

Views: 3131

Answers (2)

lhf
lhf

Reputation: 72422

Try this:

lua_getglobal(L,"a")
lua_rawgeti(L,-1,1)
lua_rawgeti(L,-1,2)

After this, the value of a[1][2] will be on the top of the stack. The stack will also contain a and a[1], which you may want to pop when you're done (they're left on the stack in case you want to retrieve multiple values).

Upvotes: 3

Drew McGowen
Drew McGowen

Reputation: 11716

You can use the lua_gettable method. There are a few important notes, however:

  1. Lua arrays start at index 1, not 0.
  2. You'll need to push the index onto the lua stack via lua_pushinteger.
  3. The key is "replaced" with the indexed element.

Upvotes: 6

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