tryParse static method

1. String input

Parses a string containing a number literal into a number.

Like parse, except that this function returns null for invalid inputs instead of throwing.

Examples:

var value = num.tryParse('2021'); // 2021
value = num.tryParse('3.14'); // 3.14
value = num.tryParse(' 3.14 \xA0'); // 3.14
value = num.tryParse('0.'); // 0.0
value = num.tryParse('.0'); // 0.0
value = num.tryParse('-1.e3'); // -1000.0
value = num.tryParse('1234E+7'); // 12340000000.0
value = num.tryParse('+.12e-9'); // 1.2e-10
value = num.tryParse('-NaN'); // NaN
value = num.tryParse('0xFF'); // 255
value = num.tryParse(double.infinity.toString()); // Infinity
value = num.tryParse('1f'); // null

Implementation

static num? tryParse(String input) {
 String source = input.trim();
 // TODO(lrn): Optimize to detect format and result type in one check.
 return int.tryParse(source) ?? double.tryParse(source);
}