js indexof string
//indexOf - JS method to get index of array element.
// Returns -1 if not found
var colors=["red","green","blue"];
var pos=colors.indexOf("blue");//2
//indexOf getting index of sub string, returns -1 if not found
var str = "We got a poop cleanup on isle 4.";
var strPos = str.indexOf("poop");//9
//Eg with material ui
<Checkbox
checked={value.indexOf(option) > -1}
value={option}
/>
"Blue Whale".indexOf("Blue"); // retorna 0
"Blue Whale".indexOf("Blute"); // retorna -1
"Blue Whale".indexOf("Whale", 0); // retorna 5
"Blue Whale".indexOf("Whale", 5); // retorna 5
"Blue Whale".indexOf("Whale", 7); // retorna -1
"Blue Whale".indexOf(""); // retorna 0
"Blue Whale".indexOf("", 9); // retorna 9
"Blue Whale".indexOf("", 10); // retorna 10
"Blue Whale".indexOf("", 11); // retorna 10