js eval function code example
Example 1: Calculate string value in javascript, not using eval
let str = "12/5*9+9.4*2"
let res1 = eval(str)
console.log('res1:', res1)
let res2 = (new Function('return '+str)())
console.log('res2:', res2)
Example 2: javascript execute string code
var theInstructions = "alert('Hello World'); var x = 100";
var F=new Function (theInstructions);
return(F());
Example 3: what is eval in js
The eval() function evaluates JavaScript code represented as a string.
console.log(eval('2 + 2'));
console.log(eval(new String('2 + 2')));
console.log(eval('2 + 2') === eval('4'));
console.log(eval('2 + 2') === eval(new String('2 + 2')));
Example 4: eval in javascript
eval() -> is able to evalute the things inside it , like eval(a+b+c) , wher a=3,b=4,c=4 , so eval(a+b+c) = 11