TypeScript：const

Use const Defined variables and uses let Defined variables have the same scope , The difference lies in the use const The defined variable cannot be re assigned later ：

const a = 1;
a = 2;//error TS2588: Cannot assign to 'a' because it is a constant.

But if const Definition is object Or variables of array type , Variables themselves cannot be reassigned , But the object or array represented by the variable can still be modified ：

const a = {
	data : 1
};
a.data = 2;
console.log(a);// Output { data: 2 }

a = {data : 1};//error TS2588: Cannot assign to 'a' because it is a constant.

const b = [1,2];
b.push(3);
console.log(b);// Output [ 1, 2, 3 ]
b = [4,5,6];//error TS2588: Cannot assign to 'b' because it is a constant.