JS Data Type Summary

1.Java Script Data type: (1) Basic types are: Number, Boolean, string, Undefined, null (2) reference types are: Native object, built-in object, host object

2. Identifiers: (1) identifiers cannot use the keyword (2) identifiers can contain letters, numbers 0-9, underscores (_), or dollar signs the first character of A $ (3) identifier must be a letter, an underscore (_), or a dollar sign $ (4) identifier is case-sensitive and does not specify a maximum length

3. Loop: (1) while loop (2) Do While loop (3) for loop

4.Switch statement: If statement creates a branch during program run, and can use else if to handle many branches however, we can use Switch,switch in the actual use of a large number of branches when we are dealing with many branches, and the code is clear. The execution is more efficient than the if branch, and the variable condition in the switch statement can be placed on any basic type

5.Java Script Process Control: There is no block scope in Java script, only the function scope, that is, the curly braces of the function can guarantee that the variables within the curly braces cannot be used outside the curly braces

5. Precedence of operators: Point operators and parentheses have the highest precedence, some special operator precedence ranked second, followed by arithmetic operators, followed by bitwise operators, relational operators, logical operators, assignment operators, and finally comma operators.

About yourself do not know the local 1.for loop, while loop and do While loop 2. Flashbacks 3. There are also problems in the process of reckoning that do not know how to express. 34. Operators are not clear about the actual use of the operator

JS Data Type Summary