This is an example of my code. I want to use my existing if/else statement inside a try-catch block, and push when validation fails. I'm trying to use try-catch in between if/else condition and it gives me an error.

var errLogs = [];
try {
  var a = "ABCD";
  if(typeof a === "string"){
     console.log("equel");
  }catch(e) {
  }else{
     console.error("not equel");
  }
  console.log(e);
  errLogs.push(e);
}

This is an example of my code. I want to use my existing if/else statement inside a try-catch block, and push when validation fails. I'm trying to use try-catch in between if/else condition and it gives me an error.

var errLogs = [];
try {
  var a = "ABCD";
  if(typeof a === "string"){
     console.log("equel");
  }catch(e) {
  }else{
     console.error("not equel");
  }
  console.log(e);
  errLogs.push(e);
}

• javascript
• arrays
• try-catch

• You should close if block within try block. – user1531038 Commented Jul 10, 2018 at 3:52

3 Answers 3

You can throw a new error to go directly to catch like:

var errLogs = [];

try {
  var a = "ABCD";   // or, test it with number 123

  if (typeof a === "string") {
    console.log("equel");
  } else {
    throw new TypeError("not equel")
  }

} catch (e) {
  console.log(e);
  errLogs.push(e);
}

DEMO:

var errLogs = [];

function testString(value) {
  try {
    if (typeof value === "string") {
      console.log("equel");
    } else {
      throw new TypeError("not equel")
    }

  } catch (e) {
    console.log(e.message);
    errLogs.push(e.message);
  }
}


testString('ABCD');
console.log('Now testing with number --->')
testString(123);

Update your code like this

var errLogs = [];

try {
  var a = "ABCD";
  if(typeof a === "string"){
    console.log("equel");
  }
  else{
    console.error("not equel");
    //you dont need else there- once exception is thrown, it goes into catch automatically
  }
}catch(e) {
        console.log(e);
        errLogs.push(e);
}

Try somthing like this.

    function IsString(d){
      try {
        if(typeof d==='string'){
          return {isString:true,error:""}; 
        }
          return  {isString:false,error:`data type is ${typeof(d)}`}; 
        } catch (err) {
           return  {isString:false,error:`error:${e}`}; 
        }
    }
    
    //TEST CASE
    let errorLogs=[]
    
    //#1
    let check1=IsString(null);
    errorLogs.push(check1)
    
    //#3
    let check2=IsString(123);
    errorLogs.push(check2)
    
    //#4
    let check3=IsString('');
    errorLogs.push(check3)
    
    //#5
    let check4=IsString('');
    errorLogs.push(check4)
    
    //Output
    console.log(errorLogs)