I have an issue with my if statement it generates warning? : Hello im trying to make a calculator, but my if statement generate warnings. Im am also new to c.

int main(){

	float num1;
	float num2;
	
	char input[5];
	
	printf("Hello my name is baymax\n");
	printf("Enter either add, sub, mult, div:\n");
	scanf("%4s", input);
	
	printf("Enter first number\n");
	scanf("%f", &num1);
	
	printf("Enter second number\n");
	scanf("%f", &num2);
	
	if(input == 'add'){
		printf("%.1f + %.1f = %.1f",num1, num2, num1+num2);
	....
	}
    return 0;
}

if the string entered is add it will add the two numbers.