dReplaceString method
字符串替换
start 起始位置
end 结束位置
replacement 替换内容
Implementation
String dReplaceString(
{int start = 3, int end = 7, String replacement = '****'}) {
if (start < 0 || length < end || start > end) return this;
return replaceRange(start, end, replacement);
}