JavaScript Learning-Numeric and string conversions

Numeric and string conversions

In a blog post I wrote a string cut here I write down, converting between strings and numbers.

Number

The simple thing is to convert a numeric string into an integer.
The code is as follows:

var"12345";varNumber1//num_a的值是: 12346

If we were to intercept a number in a string, we would need to use the string cut that was said in the previous blog post. What if I don't cut it?

var"iamalps1992";varNumber// num输出为 NaNnum = str.subString(711Number//num输出为 1992

The following are the properties of some of the objects of Number: (Table content from: W3cschool)

Properties	Description
Constructor	Returns a reference to the number function that created this object
Max_value	The maximum number that can be represented.
Min_value	The smallest number that can be represented.
NaN	Non-numeric value.
Negative_infinity	Negative infinity, which returns this value when overflow.
Positive_infinity	Positive infinity, which returns this value when overflow.

Tostring

When we have finished manipulating the numbers, we might prefer to have a string, because many operations are string-based.

In particular, the ID on my previous page was a letter that started with letters, but the numbers were ordered sequentially, and I wanted to increase it by 1 each time id . Then you can just take the numbers out and +1 convert them to strings.

ToString () is a method of the Number object

The method is simple:

NumberObject.toString(radix);

Parameters	Description
Radix	Optional. An integer that specifies the cardinality of the number that makes 2 ~ 36. If this argument is omitted, cardinality 10 is used. Note, however, that if the parameter is a value other than 10, the ECMAScript standard allows the implementation to return any value. Content Source: W3cschool

Here is an example:

str"iamalps1992"str.subString(7111;strstr.subString(07//不写radix默认是10进制str//输出: iamalps1993

Roughly, it's easier.

Number Object method

Method	Description
Tostring	Converts a number to a string, using the specified cardinality.
toLocaleString	Converts a number to a string, using the local number format order.
ToFixed	Converts a number to a string, the result of which has a specified number of digits after the decimal point.
Toexponential	Converts the value of an object to an exponential count method.
Toprecision	Formats the number as the specified length.
ValueOf	Returns the base numeric value of a number object.

Content Source: W3cschool

JavaScript Learning-Numeric and string conversions