Javascript Recursion | Mr Yenagandula

Recursion In Detail

• The main intention of recursion in javascript to avoid more logic and Recursion is a process of calling method itself until get the desired output
• To achive recursion we need one base condition in side recursion method to stop the process after received output.
• If the the condition is not there it will be in looped mode and the page willbe idle. (Meaning The stack memory is full and will get a exception)
• we can also avoid for loops using recursion.

Steps:

• Create function in javascript file.
• Add the base condition in side method.
• call the method from inside method and outside method.

Example (1)

  function consoleLogBasedOnCondition(index, times){
    /** Adding base condition and also stop the condition using return. */
    if(index === times){
        console.log("we got output.");
        return;
    }
    console.log('index value is ',index);

    /** Calling same method until condition satisfied. */
    consoleLogBasedOnCondition(index+1,times)
  }
  consoleLogBasedOnCondition(1, 5);

Example (2)

  function fibanacciSeriesByRecursion(num){
    if(num < 2 ){ 
        return num;
    }

    return fibanacciSeriesByRecursion(num-1) + fibanacciSeriesByRecursion(num - 2);
  }

  const value = fibanacciSeriesByRecursion(5);
  console.log('fibanocci value is' + value);