How can i find the index of specific value inside an array?

I have an array lets say 1x4 with these values : [ 2 4 6 8 ] .How can i find the index that 4(index 2 of the array) is stored for example and then save it to some variable?

Answer 1

[Gn Gnk]

index=find(M==4) % M=[2 4 6 8];

returns the index 2 i wanted

[madhan ravi]

Isn’t that what I answered?

[Gn Gnk]

Yes , i indeed searched find .I just wanted to give a detailed solution for anyone who has the same problem.

Answer 2

[madhan ravi]

doc find