why this error is appearing

my code is ,

/**
 * @param {number[][]} points
 * @return {number}
 */
var maxPoints = function(points) {
    n=0
    for(let i=0;i<=points.length;i  ){
    let x=points[i]
    const y=points[i 1]
    let dx=y[0]-x[0]
    let dy=y[1]-x[1]
    m=dy/dx
    b = y[1]-m*y[0]
    newy=m*y[0] b
        if(newy==y[1]){
            n  
        }
        console.log(y)
    }
    return(n)
};

Error

Line 10 in solution.js
    let deltax=y[0]-x[0]
                ^
TypeError: Cannot read properties of undefined (reading '0')
    Line 10: Char 17 in solution.js (maxPoints)
    Line 31: Char 19 in solution.js (Object.<anonymous>)
    Line 16: Char 8 in runner.js (Object.runner)
    Line 22: Char 26 in solution.js (Object.<anonymous>)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Object.Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Module.load (node:internal/modules/cjs/loader:981:32)
    at Function.Module._load (node:internal/modules/cjs/loader:822:12)
    at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
    at node:internal/main/run_main_module:17:47

Question is find the max number of points to draw a straight line from the given array of points how to solve this error

CodePudding user response：

I'm not clear on your overall goal here, or the expected structure of points, but I can see the cause of the specific error.

Let's say the array points has 4 items. Your loop continues while i <= points.length, i.e. <= 4 in our example. However, arrays are zero-indexed in JavaScript, so i[4] will be undefined.

Adding to that, you assign y to points[i 1]. In our example, when i is 3, i 1 will be 4 - so y will be undefined - when you attempt to access y[0] here, y will be undefined and not an array, so accessing [0] will fail.

CodePudding user response：

change loop condition to i<points.length