javascript judges integer methods to share

There are two ways to judge integers: regular judgment and verbatim judgment.

Because verbatim judgment is too inefficient, I won't describe it here, interested viewers can Google.

1. Regular judgment

var r = /^\+?[1-9][0-9]*$/;　　// Positive integer  

console.log(r.test(1.23));

Effect test:
http://jsfiddle.net/wzsdp9Lc/

Extended feature list

"^\\d+$"　　// Non-negative integer (positive integer)  + 0 ) 

"^[0-9]*[1-9][0-9]*$"　　// Positive integer 

"^((-\\d+)|(0+))$"　　// Non-positive integer (negative integer)  + 0 ) 

"^-[0-9]*[1-9][0-9]*$"　　// Negative integer 

"^-?\\d+$"　　　　// The integer 

"^\\d+(\\.\\d+)?$"　　// Nonnegative floating point number (positive floating point number)  + 0 ) 

"^(([0-9]+\\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\\.[0-9]+)|([0-9]*[1-9][0-9]*))$"　　// Are floating point Numbers 

"^((-\\d+(\\.\\d+)?)|(0+(\\.0+)?))$"　　// Non - positive floating point number  + 0 ) 

"^(-(([0-9]+\\.[0-9]*[1-9][0-9]*)|([0-9]*[1-9][0-9]*\\.[0-9]+)|([0-9]*[1-9][0-9]*)))$"　　// Negative floating point number 

"^(-?\\d+)(\\.\\d+)?$"　　// Floating point Numbers 

2. Judge
by rounding

The idea of this method is to judge whether it is equal to the original value

after taking the integer

var num=1.23;

if (parseInt(num) != num) {

    console.log(num+" As an integer ");

}

else{

    console.log(num+" As an integer ");

}

Effect test
http://jsfiddle.net/euvn0L1g/1/