nan in php

In javascript, how does one determine whether a variable is null, undefined, Or NaN? Let's take a look at the specific judgment method. It is mainly determined through the typeof method. typeof returns a string and has six possible results: "number",

Php array declaration, traversal, array global variables. Php Tutorial array declaration, traversal, array global variable [php]? ** 1. Array Overview * 1. the essence of arrays: managing and operating a group of variables, batch processing * 2.

The boss always wants me to recruit some Java programmer to do ...? He (old person) outside and other camp engineers talk more and will always come to ask me, you always play PHP (framework), But after our website fire, load up ... PHP does not

The essence of arrays: manages and operates a group of variables and processes them in batches. The following describes the array classification, array classification, and usage instructions. Php Tutorial: Array declaration, traversal, array global

Php Tutorial: array declaration, traversal, array global variables Copy codeThe Code is as follows: /* * 1. array Overview * 1. The essence of Arrays: managing and operating a group of variables, batch processing * 2. array composite type (multiple

PHP Tutorial: Array declaration, traversal, array global variables Copy CodeThe code is as follows: /* * First, an overview of arrays * 1. The nature of the array: managing and manipulating a set of variables, batch processing * 2. Compound type

About the multi-dimensional array, [["name"=>"zs","age"=>"10","sex"=>"nan"],["name"=>"ls","age"=>"11","sex"=>"nan"],["name"=>"ww","age"=>"12","sex"=>"nv"]], [["name"=>"zs","age"=>"10","sex"=>"nan"],["name"=>"ls","age"=>"11","sex"=>"nan"],["name"=>

This article mainly introduces the knowledge of the basic JavaScript type value-Number type, which has good reference value. Let's take a look at it below. Overview In JavaScript, numbers are represented in the IEEE754 format. Therefore, integers

[["Name" = "Zs", "age" = "ten", "Sex" and "Nan"],["name" = "ls", "age" = "one", "sex" = "nan"],["name" = > "ww", "Age" and "ten", "Sex" and "NV"], [["Name" + "Zs", "age" = "+", "sex" = "nan"],["name" = "ls", " Age "+", "Sex" and "Nan"],["name" = "ww"

Php learning notes array traversal implementation code. Copy the code as follows :? Php * array traversal ** 1. use the for statement to traverse the array cyclically * 1. other languages (only in this way) * 2. this method is not the preferred