Rest API to check field value contains...

[site url]/_api/Web/Lists/GetByTitle('myList')/items/?$filter=substringof('ABC',Title)

Filter Unique Value in Array

var items = ['abc','pqr','abc','xyz','pqr','abc'];
var result = items.filter(UniqueElement); 

//result ['abc', 'pqr','xyz']


function UniqueElement(value, index, self) { 
    return self.indexOf(value) === index;
}

Simple way to Check if JSON is correct or not..

function IsJsonString(str) {
    try {
        JSON.parse(str);
    } catch (e) {
        return false;
    }
    return true;
}

Remove control characters from a string

function removeCC(s) {

  /* Remove NewLine, Carriage Return and Tab characters from a String  */

  r = "";
  for (i=0; i < s.length; i++) {
    if (s.charAt(i) != '\n' &&
        s.charAt(i) != '\r' &&
        s.charAt(i) != '\t') {
      r += s.charAt(i);
      }
    }
  return r;
  }

Same thing with regular expression

function removeCC(s){ 
  return s.replace(/[\n\r\t]/g," "); 
}

Custom button in DataTable

DataTable Example:

(1)Add custom button

"buttons": [{"text": ' Custom Button',
        "action": function () {
                                alert("Custom Button Clicked");
}
        },

]


(2) Button Menu

"buttons":[
                {
                extend: 'collection',
                text: 'Menu',
                className: "menuMain",
                autoClose: true,
                buttons: [
                    {
                        text: 'Item 1',
                        action: function () {
                            alert("Item 1 Selected");
                        }
                    },
                    {
                        text: 'Item 2',
                        action: function () {
                            alert("Item 2 Selected");
                        }
                    }
                ]                           
                             },
                  ]

Get index from a JSON object with value

var data = [{"name":"placeHolder","section":"right"},{"name":"Overview","section":"left"},{"name":"ByFunction","section":"left"},{"name":"Time","section":"left"},{"name":"allFit","section":"left"},{"name":"allbMatches","section":"left"},{"name":"allOffers","section":"left"},{"name":"allInterests","section":"left"},{"name":"allResponses","section":"left"},{"name":"divChanged","section":"right"}];

// Google Chrome user.
var index = data.findIndex(obj => obj.name=="allInterests");

console.log(index);


// for IE user

var index = -1;
for (var i = 0; i < data.length; ++i) {
    if (data[i].name == "allInterests") {
        index = i;
        break;
    }

}

console.log(index);

how to use toLocaleString() and tofixed(2) in javascript

numObj.toLocaleString([locales [, options]])

toLocaleString takes 2 arguments. The first is the locale, the second are the options. As for the options, you are looking for:

minimumFractionDigits

The minimum number of fraction digits to use. Possible values are from 0 to 20; the default for plain number and percent formatting is 0; the default for currency formatting is the number of minor unit digits provided by the ISO 4217 currency code list (2 if the list doesn't provide that information).

To be able to set the options without setting the locale, you can pass undefined as first argument:

var num = 2046430;
num.toLocaleString(undefined, {minimumFractionDigits: 2}) // 2,046,430.00

However this also allows the fraction to be longer than 2 digits. So we need to look for one more option called maximumFractionDigits. (Also on that MDN page)

var num = 2046430.123;
num.toLocaleString(undefined, {
  minimumFractionDigits: 2,
  maximumFractionDigits: 2
}) // 2,046,430.12