To recognize a number in a string and to be sure that the algorithm uses the value of a variable whose type is a number is necessary in almost every algorithm. The parseInt JavaScript method solves this problem and allows you to recognize numerical values in popular number systems.
ParseInt Method Syntax
The method takes two parameters, the second of which is optional. The result of the work is always a number. If the first parameter (string) does not contain the number system at the beginning, then the result will be NaN.
Hexadecimal digits include the letters: 'a', 'b', 'c', 'd', 'e' and 'f'. The sign of the octal number is the leading '0', and the hexadecimal starting pair is '0x'. But not always the conversion will be performed correctly, although it is syntactically indicated correctly.
The function of parsing numbers is a popular operation. In the simplest case, the parseInt JavaScript and prompt methods let you filter the input of the correct numerical values for quick decisions.
Note. Function promt () - enters what the visitor typed in the input field, and not the "result" of the Ok or Cancel buttons. That is why, to get fast values, you can track the content of the visitor’s input on the fly and make the right decision.
Using the parseInt Method
Internet programming has its own specifics and has a strong influence on programming ideas in general. The merging of small data into one capacious “word” is a parameter whose main qualities are:
- compactness;
- fast recognition.
In many cases, the biggest "lovers" of this factor, CSS and HTML, began to write a number, and then immediately without a space, a unit of measure or a punctuation mark. In other words, to make up strict character sequences.
Regular expressions in general, for the uninitiated in the sacraments of parsing, are Morse code, in which porridge from dots and dashes is "divorced" into almost all the characters of the traditional eight-bit set. Moreover, everything that is not included in the visible part of the symbol table can be easily painted with codes, that is, numbers and letters - this is the JavaScript parseInt method.
Many parameters of some CSS functions do not allow a space, and only work when they are written exclusively to the exact standard.
XML, with all its openness, does not allow liberties when encoding parametric information.
There are many examples of the demand for parsing numerical information outside of JavaScript, but this does not play a role. The value of the parseInt JavaScript method depends on the role that numerical information plays and how it has become customary to present it in a wide variety of applications.
Numerical parsing value
Parsing information is a symbolic procedure, but programming today is still the same processing of numerical information as it was three decades ago. There was no JavaScript & parseInt in the past. But it was from the experience of the past that knowledge about the processing of numerical information came; the potential for regular expressions and other similar ideas was accumulated.
In a certain period of time, programming languages allowed “liberties” in keywords, “unblocked” the Cyrillic alphabet, and allowed the developer to process weakly formalized data. But this period was short, and with a growing interest in object-oriented programming, a "black hole" formed, meanwhile:
The modern programming language in general (although the value of the JavaScript language is difficult to evaluate in general) is required to separate the work tool from the subject matter. The tool must be accurate and fast, and the subject of work can be arbitrarily large and practically unformalized. But the result of the program with each moment of time becomes more significant.
Developing objects without JavaScript parseInt is an unjustified waste of effort, time and code. Object methods should work like clockwork, quickly and accurately. But the object for the work of the object is information, the result of the work of the object is also information. And here, to understand an object is not necessarily the concept of JavaScript, PHP or Python ... these are particular options and coding styles of real objects.