I am writing a simple js/es5 script to combine all the strings in a CWL. The CWL only supports ES5, so there are many functions/features from ES6 cannot be used. I am not familiar with js in general.
For a minimal example:
var arr1 = ["a", "b"]
var arr2 = ["111", "222"]
Expected result:
["a_111", "b_111", "a_222", "b_222"] // order doesn't matter
I tried this way, but it did not work and only returned ["a_111", "b_111"]
arr1.map(function(x) {
return arr2.map(function(y) {
return x + "_" + y;
});
});
I wouldn't bother using map for this. Just have a nested loop and push a string into a new array.
var arr1 = ['a', 'b'];
var arr2 = ['111', '222'];
var out = [];
for (var i = 0; i < arr2.length; i++) {
for (var j = 0; j < arr1.length; j++) {
var str = arr1[j] + '_' + arr2[i];
out.push(str);
}
}
console.log(out);What you can use is a combination of reduce(), concat() and map():
let result = arr1.reduce((acc, a) => acc.concat(arr2.map((b) => a + "_" + b)), []);
// => [ 'a_111', 'a_222', 'b_111', 'b_222' ]
Alternatively when flat() is available you can use:
let result = arr1.map((a) => arr2.map((b) => a + "_" + b)).flat();
// => [ 'a_111', 'a_222', 'b_111', 'b_222' ]
I am not sure if flat() works with ES5 though.