Why eval (" 14 "+" 2 ") is the result of the 142, and eval (" 2 * 7 "+" 2 ") is the result of the 144, and eval (" 5 + 9 "+" 2 ") is 97

So the eval () what's the use, in where, what is a working principle

CodePudding user response:

Eval is to put the string expressions into python statement execution,
Eval (" 14 "+" 2 ") is the result of the 142 because are two strings together, rather than "14 + 2", so it is 142 instead of 16

Eval (" 2 * 7 "+" 2 ") is the result of the 144, is the same reason, so understanding: eval there are two strings, the addition of the string is connected, becomes a python implementation "2 * 72" this statement, so the result is 144,

Can print (" 2 * 7 "+" 2 "), the output of 2 * 72, and eval is merely to its execution

CodePudding user response:

By the way, to understand this in addition to the above said, and calculating priorities, in parentheses to perform first, so the strings up first,

CodePudding user response:

With your ideas, the results should be?

CodePudding user response:

"14" + "2" rather then "142", but that's just split the string, so the eval (" 14 "+" 2 ") is the eval (" 142 "), which is 142

CodePudding user response:

Have priority, to merge the string operation again, it's all said