Cant change GO material with multipli material

Questions & Answers
1

when i do that it work only with the first material

ITEM1.gameObject.renderer.materials=PE.gameObject.renderer.materials;

but when i do that it doesnt work

ITEM1.gameObject.renderer.materials[1]=PE.gameObject.renderer.materials[0];

how can i change my ITEM1 second material with my PE first material?

2

var mats = PE.gameObject.renderer.materials;
mats[0] = ITEM1.gameObject.renderer.materials1;
ITEM1.gameObject.renderer.materials = mats;

Renderer.materials** If you want to change some materials in it, get the value, change an entry and set materials back**