Let $C_c (\mathbb{R}) = \{f : \mathbb{R} \to \mathbb{R} \mid f$ is continuous and there exists a compact set $K$ such that $f = 0$ on $K^c\}$.
Let $g(x) = \exp(-x^2)$.
Is the following statement true?
If a sequence in $C_c (\mathbb{R})$ converges pointwise to $g$, then it must converge uniformly to $g$.
The statement is not true.
Consider $h_n$ a sequence who uniformly converges to $g$ and let $f_n=h_n+b_n$ where $b_n$ is a hat function with its maximum located at $n$ of value $1$ and a base of width $1$.
Then $\|f_n-g\|_{\infty} \to 1$ (hence we do not have uniform convergence) but $f_n$ converges pointwise to $g$.