Range Over Built in Minitab

range iterates over elements in a variety of built-in data structures. Let’s see how to use range with some of the data structures we’ve already learned.

Here we use range to sum the numbers in a slice. Arrays work like this too.

```javascript
let nums = [2, 3, 4];
let sum = 0;
for (let num of nums) {
    sum += num;
}
console.log("sum:", sum);

range on arrays and slices provides both the index and value for each entry. Above we didn’t need the index, so we ignored it with the blank identifier _. Sometimes we actually want the indexes though.

for (let i in nums) {
    let num = nums[i];
    if (num == 3) {
        console.log("index:", i);
    }
}

range on map iterates over key/value pairs.

let kvs = {"a": "apple", "b": "banana"};
for (let k in kvs) {
    let v = kvs[k];
    console.log(`${k} -> ${v}`);
}

range can also iterate over just the keys of a map.

for (let k in kvs) {
    console.log("key:", k);
}

range on strings iterates over Unicode code points. The first value is the starting byte index of the rune and the second the rune itself.

for (let i in "go") {
    let c = "go".charCodeAt(i);
    console.log(i, c);
}

To run this JavaScript code, you can use node from the command line:

$ node script.js

Next example: Pointers.

Recursion in Minitab

Pointers in Minitab

Learn X By Example

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Range Over Built in Minitab