double question mark operator means “if null “. Take the following expression, for example. String a = b ?? ‘hello’; This means a equals b , but if b is null then a equals ‘hello’ .4 Oca 2019
Read moredouble question mark operator means “if null “. Take the following expression, for example. String a = b ?? ‘hello’; This means a equals b , but if b is null then a equals ‘hello’ .4 Oca 2019
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