JS get the substring of the specified character position and the specified character position interval of the specified string [simple and detailed]

Js Gets the specified character position of the specified string & Specifies the substring of the character position interval

1. Gets the location of the specified character

-- Sample string 
var  currentJsonRow.TRADE_TYPE='[1001] Bonded ';

grammar : character string .substring(" Specify the characters ")

--- Example 
currentJsonRow.TRADE_TYPE.substring("[")
 result : '[1001] Bonded '

2. Get the substring of the specified character interval

The first one is : prevent IE Incompatible ( I really vomited in some factories ~! Just like IE… The right eyelid jumped again >…<)

For example, get the first [] The substring inside the brackets

Just look at the code below !( Very intuitive !!)

currentJsonRow.TRADE_TYPE.substring(currentJsonRow.TRADE_TYPE.indexOf("[")+1,currentJsonRow.TRADE_TYPE.indexOf("]"))
 result :   '1001'

The second kind : Regular expressions (YYDS!_ ok )

grammar :/(?<=\[)(.+?)(?=\])/g

// Get the data in brackets  
TRADE_TYPE_NUM = currentJsonRow.TRADE_TYPE.match(/(?<=\[)(.+?)(?=\])/g)[0];

[ The following business code , Don't look _^^]

  // Add judgement -- Selected condition increase 
                    if ($("[id$=hidShopID]").val() == "G181") {
    
                        if (currentJsonRow.TRADE_TYPE.match(/(?<=\[)(.+?)(?=\])/g) != null || currentJsonRow.TRADE_TYPE.match(/(?<=\[)(.+?)(?=\])/g) != undefined) {
    
                            TRADE_TYPE_NUM = currentJsonRow.TRADE_TYPE.match(/(?<=\[)(.+?)(?=\])/g)[0];
                        } else {
    
                            TRADE_TYPE_NUM = currentJsonRow.TRADE_TYPE.split('|')[0];
                        }
                        if (TRADE_TYPE_NUM == " All " || TRADE_TYPE_NUM == null || TRADE_TYPE_NUM == undefined) {
    
                            xAlert(">>^=^<<");
                            return;
                        }
                    }