Nodejs String Starts With startsWith(string)

Method Source Code

String.prototype.startsWith = function(string){
  if (typeof(string) !== "string") {
    throw new Error("Input argument was not a string");
  } else if (this.substring(0, string.length) === string) {
    return true;//  ww  w  .jav  a 2  s. c om
  } else {
    return false;
  }
};

Related

1. startsWith(str)

   String.prototype.startsWith = function(str) {
       return this.substr(0, str.length) == str;
   String.prototype.endsWith = function(str) {
       return this.substr(this.length - str.length) == str;
   

2. startsWith(str)

   String.prototype.startsWith = function(str) {
       return this.indexOf(str) === 0;
   };
   

3. startsWith(str, ignoreCase)

   String.prototype.startsWith = function(str, ignoreCase) {
     return (ignoreCase ? this.toUpperCase() : this)
       .indexOf(ignoreCase ? str.toUpperCase() : str) == 0;
   };
   

4. startsWith(string)

   String.prototype.startsWith = function (string) {
     var index = arguments.length < 2 ? 0 : arguments[1];
     return this.slice(index).indexOf(string) === 0;
   };
   

5. startsWith(string)

   String.prototype.startsWith = function (string) {
     var index = arguments.length < 2 ? 0 : arguments[1];
     return this.slice(index).indexOf(string) === 0;
   };
   

6. startsWith(string)

   String.prototype.startsWith = function (string){
     return this.indexOf(string) === 0;
   };
   

7. startsWith(substr)

   String.prototype.startsWith = function(substr) {
       for (var i = 0; i < substr.length; i++) {
           if (this[i] !== substr[i]) {
               return false;
       return true;
   

8. startsWith(substr)

   String.prototype.startsWith = function(substr) {
     return (this.indexOf(substr) == 0);
   };
   

9. startsWith(substring)

   String.prototype.startsWith = function (substring) {
       var stringCut = this.substring(0, substring.length);
       return stringCut === substring;