Characters allowed before javascript URL

if (new URL(String.fromCodePoint(0) + "javascript:alert()").protocol=="javascript:"){alert(0)}

if (new URL(String.fromCodePoint(1) + "javascript:alert()").protocol=="javascript:"){alert(1)}

if (new URL(String.fromCodePoint(2) + "javascript:alert()").protocol=="javascript:"){alert(2)}

if (new URL(String.fromCodePoint(3) + "javascript:alert()").protocol=="javascript:"){alert(3)}

if (new URL(String.fromCodePoint(4) + "javascript:alert()").protocol=="javascript:"){alert(4)}

if (new URL(String.fromCodePoint(5) + "javascript:alert()").protocol=="javascript:"){alert(5)}

if (new URL(String.fromCodePoint(6) + "javascript:alert()").protocol=="javascript:"){alert(6)}

if (new URL(String.fromCodePoint(7) + "javascript:alert()").protocol=="javascript:"){alert(7)}

if (new URL(String.fromCodePoint(8) + "javascript:alert()").protocol=="javascript:"){alert(8)}

if (new URL(String.fromCodePoint(9) + "javascript:alert()").protocol=="javascript:"){alert(9)}

if (new URL(String.fromCodePoint(10) + "javascript:alert()").protocol=="javascript:"){alert(10)}

if (new URL(String.fromCodePoint(11) + "javascript:alert()").protocol=="javascript:"){alert(11)}

if (new URL(String.fromCodePoint(12) + "javascript:alert()").protocol=="javascript:"){alert(12)}

if (new URL(String.fromCodePoint(13) + "javascript:alert()").protocol=="javascript:"){alert(13)}

if (new URL(String.fromCodePoint(14) + "javascript:alert()").protocol=="javascript:"){alert(14)}

if (new URL(String.fromCodePoint(15) + "javascript:alert()").protocol=="javascript:"){alert(15)}

if (new URL(String.fromCodePoint(16) + "javascript:alert()").protocol=="javascript:"){alert(16)}

if (new URL(String.fromCodePoint(17) + "javascript:alert()").protocol=="javascript:"){alert(17)}

if (new URL(String.fromCodePoint(18) + "javascript:alert()").protocol=="javascript:"){alert(18)}

if (new URL(String.fromCodePoint(19) + "javascript:alert()").protocol=="javascript:"){alert(19)}