The implicit type conversion in JS

1. When math is in operation

var num = + ' 123 ';

var num1 =-' 123 ';

var num2 = ' 123 '/1;

Console.log (typeof Num1)

Console.log (typeof num)

2.new operator

var num = new number (' Hello ');

Console.log (num)

3 string concatenation no matter the value of any other data type is spliced with a string, it will become a string

var ret = ' 123 ' +456;//123456

var Ret2 = ' 123 ' +{}//object? ' 123[object Object] '

var ret3 = ' 123 ' +[3,4,5]//' 1233,4,5 '

The conversion of an array into a string is a special form that translates into ' 3,4,5 '

Console.log (ret)

Console.log (Ret2)

Console.log (RET3)

Array 456 is converted to a string, followed by string concatenation with the preceding string ' 123 '

Console.log (typeof (new number). ToString ())//String data type

4 If Judgment statement

The IF (' Chuanzhi ') {//if judgment statement internally converts the value of the other data type to a Boolean data type and then determines

Console.log (' Chuanzhi ')

}

The implicit type conversion in JS