JavaScript data type conversion (Parseint,parsefloat) _ Basics

JavaScript has two conversion methods for data types:

(i) converting an entire value from one type to another (called a basic data type conversion)

(ii) Extract the value of another type from one value and complete the conversion work



Three ways to convert basic data types:

1. Convert to Character type: String (); Example: The result of String (678) is "678"
2. Convert to Numeric type: number (); Example: The result of number ("678") is 678
3. Convert to Boolean: Boolean (); Example: Boolean ("AAA") results are true



The method of extracting a value from a value of another type:

1. Extract the integer in the string: parseint (); Example: The result of parseint ("123zhang") is 123
2. Extract the floating-point number in the string: parsefloat (); Example: The result of parsefloat ("0.55zhang") is 0.55
3. Execute a section of JavaScript code represented by a string: eval (); Example: The result of Zhang=eval ("1+1") zhang=2

Note: The number, String function is a special function, in the JS engine, he will automatically judge whether it is a constructor call or a normal call, so you can use the New keyword, can also be called as a function directly.