tryParse method - bool class - dart:core library (original) (raw)

tryParse static method

1. @Since("3.0")

bool? tryParse(

1. String source, {
2. bool caseSensitive = true, })

Parses source as an, optionally case-insensitive, boolean literal.

If caseSensitive is true, which is the default, the only accepted inputs are the strings "true" and "false", which returns the results true and false respectively.

If caseSensitive is false, any combination of upper and lower case ASCII letters in the words "true" and "false" are accepted, as if the input was first lower-cased.

Returns null if the source string does not contain a valid boolean literal.

If the input can be assumed to be valid, use bool.parse to avoid having to deal with a possible null result.

Example:

print(bool.tryParse('true')); // true
print(bool.tryParse('false')); // false
print(bool.tryParse('TRUE')); // null
print(bool.tryParse('TRUE', caseSensitive: false)); // true
print(bool.tryParse('FALSE', caseSensitive: false)); // false
print(bool.tryParse('NO')); // null
print(bool.tryParse('YES')); // null
print(bool.tryParse('0')); // null
print(bool.tryParse('1')); // null

Implementation

@Since("3.0")
external static bool? tryParse(String source, {bool caseSensitive = true});