Modern languages using that syntax tend to prevent that mistake by either outright disallowing assignments in boolean contexts, or by not having implicit conversion of other types to boolean, meaning that the mistake would be limited to the case of comparing a boolean variable to another value, which is quite rare. Some languages further limit the risk by making variables unmodifiable by default, meaning that it would have to be an explicitly modifiable boolean variable.
Assignment is one of the most frequent operations in typical programming languages, so it makes sense for it to be a single-character symbol, and ‘=’ is about the only fitting ASCII symbol for that. (With non-ASCII, there would be ‘≔’ or ‘←’ (the latter being used by APL), but those are non-obvious to type.)
Assignment is one of the most frequent operations in typical programming languages, so it makes sense for it to be a single-character symbol, and ‘=’ is about the only fitting ASCII symbol for that. (With non-ASCII, there would be ‘≔’ or ‘←’ (the latter being used by APL), but those are non-obvious to type.)