JS Learning Note (ii) operators and Process Control statements

The operators and Process control, loop, and judgment statements in JS are basically consistent with C #, but have their own unique operators.

typeof operator

　Data types such as number,string are obtained.
Grammar:
String typeof (variable);
such as Var num=123;
typeof num; or typeof (Num);

equal to and not equal to (2 kinds)
= = and! =
Only see if the result is the same (implicit conversion problem)
= = = and !==
See if the type is consistent with the result

Key-Value Form

When the literal value of an object is declared as var o = {name1: "Zhang San", Nuam2: "John Doe", Name3: "Harry", Numa4: "Zhao Liu", name5: "Chen Qi"};
Key-value pair form, the corresponding data member can be obtained by o["Name1".
　　

for-in

Is the foreach in C #
for (var i in collection) {

}

JS Learning Note (ii) operators and Process Control statements